In Chinese historical records, the earliest record about Iran comes from Sima Qian's historical records. "Historical records · biographies of Dawan" records: "rest in the west of Dayue for thousands of miles." The Parthian Empire (247 B.C. - 224 A.D.) fought against the Roman Empire and flourished for a time. "The book of Wei · biography of the western regions" records: "the capital of Persia is Suli City, and the ancient Tiaozhi country is also located in Mimi." The "Persia" here is the Sassanian Dynasty (224-651 A.D.), which is also translated into the Sassanian Dynasty, and is named after Sassanian, the grandfather of its founder aldasher. Sashan was a Zoroastrian priest. His son papek basically got rid of the rule of the Sabbath empire after controlling most parts of Fars Province in the early 3rd century. In 224, aldasher, the son of papek, set up an army to establish the Sassanid Dynasty; In 226, he occupied taixifeng, known as "the king of kings", creating a great cause of the Empire. The territory of the Sassanian Empire covers the vast area to the west of the Congling mountains, and once occupied Tashkent, guarding the throat of East-West transportation. It is a necessary place for the silk road. After the fall of the kusana empire in 425 ad, sassanpos played an important role in the Silk Road trade. Persians are not only the main consumers of Chinese silk, but also almost monopolize the transit trade of the Silk Road, which cannot be matched by Byzantines, Turks and Sogdians. The talented and profitable Persians are the most active middlemen in the trade between Europe and the Far East, and Persian has even become the "common language on the Silk Road". The Silk Road business activities greatly promoted the prosperity and development of the social economy and culture of the Sassanian empire. On the basis of inheriting the Persian traditional culture of the Achaemenid Dynasty, the Sassanian Dynasty absorbed the achievements of eastern and Western civilizations and created a brilliant Sassanian culture. According to the third volume of the compilation of historical materials of communication between China and the West compiled by Zhang Xingzhen and revised by Zhu jieqin, "in the late Sassanian Dynasty, the method of raising silkworms and drawing silk has been spread from China to Persia". Persian silk fabrics are collectively referred to as "Persian brocade", which is colorful, high-quality and popular for a time. The auspicious pattern of "Sassanian style" has a far-reaching impact on the development of Arts and crafts in China, Byzantium, Egypt and other places. The establishment of the Tang Dynasty in 618 opened a new era of Sino foreign exchanges. According to the decrees of the early Tang Dynasty, foreign protons and stranded envoys were subordinate to the 16th General of the central guard, who lived in the capital. Persians can take part in the imperial examination and intermarry with the Tang people. Those who have made outstanding contributions will be given the surname of Li, be granted an official, be promoted to general, and be buried in China after death. For example, in the early years of Emperor Taizong's Zhenguan year, an kuihan led more than 5000 people to submit to the Tang Dynasty, settled in Weizhou (now Maoxian County, Sichuan), served as the governor of Weizhou, and was awarded the Duke of Dingxiang County. During the period of Emperor Gaozong of Tang Dynasty, an Fuguo, the son of an kuihan, succeeded the governor of Weizhou, conferred Viscount, promoted to the right garrison general, and died in Chang'an. In the heyday of Tang Qiang, the silk road was unimpeded, and Hu merchants, including Persian merchants, came one after another. They brought rare birds and animals, jewelry and spices, glassware, gold and silver coins, religious beliefs, music and dance, food and clothing into the Central Plains, showing a prosperous scene. However, the Sassanian Persian Empire was in imminent danger due to the decline of the river and the wind and rain. Facing the irresistible political threat and military attack of the Arabs, King yezdigd III of Sasan (formerly translated as yisiwang and yisihou, reigned from 632 to 651) sent envoys to pay tribute to the Tang Dynasty three times (639, 647 and 648). Finally, because of the long journey, Emperor Taizong of the Tang Dynasty was unable to help. In 642, the Arab army completely destroyed the Sassanian army in najawande and conquered texiphon. Yazdigd III fled to Central Asia and died in mulu (now Southeast of Turkmenistan) in 651. The Sassanian Dynasty died. Pyrus, the son of yezdiged III, fled to tuhuoluo (now northern Afghanistan) and asked for help in the Tang Dynasty. In order to appease the exiled Persian prince, and also for the consideration of the security of the western territory, in 661, the Tang Dynasty set up the Persian governor's office in Jiling City, the capital of Sistan (now zalanji in the southwest of Afghanistan), with beibeilus as the governor. According to the fourth volume of the compilation of historical materials of communication between China and the west, "the territory under the jurisdiction of the Persian governor's office in the Tang Dynasty is only the eastern border of Persia". The following year, belus was granted the title of king of Persia by Emperor Gaozong of Tang Dynasty. According to the records of the "CE Fu Yuan GUI", Pylos twice (667 and 671) "sent envoys to the Dynasty", offered "gifts" to Emperor Gaozong of the Tang Dynasty, and personally visited China in 673. Due to the constant attack of Arabs, in 674, Beilusi took refuge in the Tang Dynasty and settled in Chang'an. Gaozong awarded him as the general of youwuwei. In 678 years, Pei Guangji, the leader of the Persian division, was also known as the leader of the khinar sect. Pei Xingjian led the army to shatiya (near today's Tokamak City, Kyrgyzstan) and then turned back. Under the strong military pressure of the Arab Empire, the Nene division remained in Tuvalu for a long time, and its subordinates were separated, with no hope of restoring the country. However, he still maintained contact with the Tang Dynasty and "sent envoys to contribute" in 682 (the first year of Yongchun, Emperor Gaozong) and 706 (the second year of Shenlong, Emperor Zhongzong). In 707, the nun division returned to Chang'an and was granted the title of general Zuo Weiwei by the emperor Zhongzong of Tang Dynasty. He soon died of illness. Pusan, the son of neneshi, was made queen of Persia and fought with Arabs in the middle of the river until 730. The Persian king in distress was eager to repair with the Tang Dynasty and frequently "sent envoys to pay tribute". Emperor Xuanzong of the Tang Dynasty pushed the new policy of "civil servants use Han people and military generals use Hu people", while Persians are like fish in water. In "the turtle of CE Fu Yuan", the Persians "pay tribute" more than ten times, reaching the peak. In 719 (the seventh year of Xuanzong Kaiyuan), the king of Persia sent envoys to pay tribute three times; 722 (the 10th year of Kaiyuan), "the Persian state sent envoys to offer lions"; In 725 (the 13th year of Kaiyuan) and 730 (the 18th year of Kaiyuan), mushano came to the DPRK twice. Both of them were "granted the right to stay and guard" and worked in Chang'an. After pusang, his descendants still sent envoys in the name of the king of Persia to pay tribute to Tang Xuanzong, offering "square things" such as rhinoceros, elephants, agate beds and non porous real beads to Tang Xuanzong. After Emperor Xuanzong of the Tang Dynasty, there were few records about the Persian king's "sending envoys to pay tribute". There were only some sporadic records in the "CE Fu Yuan GUI": offering real pearls and amber in 759 (the second year of emperor suzong Qianyuan), 762 (the first year of Emperor BAOYING of Dai Zong) and 771 (the sixth year of Dali of Dai Zong). After Tang Dezong ascended the throne in 780, there was no record of such official exchanges, but the non-governmental exchanges between China and Persia remained close. There are Persians who set up shops to do business, practice medicine, join the army and preach, whether in the two cities of the Tang Dynasty (Chang'an in the West and Luoyang in the East), the node cities along the Silk Road, Liangzhou, or the trading ports of Quanzhou and Guangzhou on the southeast coast. It is obvious from various documents that Persian immigrants almost spread all over the Tang Dynasty. In Taiping Guangji, Persians are called "Persian Hu", and there are many accounts of Persian businessmen who settled in Chang'an and engaged in jewelry, incense, medicine and other industries. "Zizhi Tongjian" said that in 787 (the third year of Zhenyuan of Dezong), "4000" Persians stayed in Chang'an, some for "more than 40 years". They "all have wives, buy fields and houses, use pledges for profits, and live in peace and do not want to return". The third volume of the compilation of historical materials of communication between China and the West wrote that "wherever the Persian footprints go, there are Yici temples". The two capitals are no exception. There are Yici (Persian Temple) in Buzheng square, Liquan square, Puning square and Jinggong square in Chang'an, Huijie square, Lide square and Nanshi west square in Luoyang. According to the records in the biography of Tang Dahe's eastward expedition written by Zhen Ren Yuankai, in 748 (the seventh year of Tianbao), the eminent monk Jianzhen drifted to Zhenzhou, Hainan Island (now Yazhou District, Sanya City) for the fifth time. He heard that the local "three-day trip from north to South, five-day trip from east to west, followed by village to village" were Persians. The Persians' entry into the Tang Dynasty strengthened the multi-ethnic consciousness of the integration of Hu and Han and the coexistence of Hu and Han. In short, in the more than 100 years after the subjugation of Sassanian Persia, the Tang Dynasty treated the descendants of the Persian royal family who were in exile, lived and stayed in the Tang Dynasty with courtesy, integrity and kindness. It is true that among the many tributaries, businessmen or other local leaders in the name of Persian envoys are not excluded. Their purpose is to use the friendly relationship between China and Persia to obtain personal security and more business interests, which ordinary Persians dream of. The silk road has witnessed the long-standing and mutually beneficial historical exchanges and friendly relations between China and Persia. The exchanges and mutual learning between the Tang Dynasty and Persia in politics, economy, military, culture, religion and art are all-round exchanges with both depth and breadth, involving the study of national history, frontier history, cultural history, language history, transportation history and so on, which is worthy of our in-depth exploration. As Mr. Peng Shuzhi, an expert in Middle East history, said in his book on civilization exchanges, "the long, extensive and interactive exchanges between Iranian civilization and Chinese civilization are an enduring and inexhaustible historical research resource". (Xinhua News Agency)