A long-awaited rain fell on Riyadh, the Saudi capital, which is located at the edge of the desert. This day is December 7, a day that attracts the attention of Saudi Arabia and many Arab countries, and a "time when distinguished Chinese guests come to the Arabian Peninsula". The ancient Arabian Peninsula, the world's shipping hub, the valve of energy supply, and the intersection of brilliant civilizations... Among many roles, they attach great importance to a definition: Chinese friends and partners. At the beginning after the rain. The sun shines through the clouds, and the earth is like a layer of dreamy golden gauze. On both sides of the special plane, four Saudi air force warplanes have been escorting all the way since their arrival. On the apron, the violet carpet is like a flower belt in the desert. Important members of the Saudi royal family and senior government officials waited under the gangway. Almost at the same time, the protocol escort plane roared past the sky, pulling out red and yellow ribbons representing the Chinese national flag; Over Riyadh, 21 gun salutes shook the sky. After the 20th National Congress of the Communist Party of China was held, the first trip to the Middle East by a Chinese head of state began. Saudi media described the three-day rich trip as the "Three Ring Summit". At the China sea level, the first China Gulf Arab States Cooperation Council Summit was held, and China and this sub regional organization had in-depth interaction. The milestone was recorded in history. At the China Arab level, the first China Arab Summit was called "a major initiative of China's diplomacy towards the Middle East since the founding of New China" and "an epoch-making milestone in China Arab relations". When partners shake hands, a new pattern of China Arab cooperation in an all-round, multi-level and wide-ranging way is slowly spreading. The four scales and one document of China Saudi Arabia relations have attracted worldwide attention. To conclude an agreement for bilateral relations is not only rare in China's diplomacy, but also in world diplomacy. It also reflects respect and care for each other's relations in the spirit of contract. There is a striking sentence in the agreement: "It is agreed to hold a summit meeting between the two heads of state every two years in turn". The rhythm of heads of state diplomacy is a vivid portrayal of state relations. From the four scales, we can trace the historical context of the development of bilateral relations. One scale: China and Saudi Arabia established diplomatic relations in 1990. Because of history, it was the last Arab country to establish diplomatic relations with China. Once the relationship between the two countries is established, the development of the relationship is unstoppable. It was also his first visit to Saudi Arabia. During the visit, China and Saudi Arabia established strategic friendly relations, and bilateral relations entered the fast lane. One scale is 2016. Go together