How can the legitimate rights and interests of buyers be protected if the developer has not obtained a pre-sale permit for commercial housing, has not completed the construction of the commercial housing, and has not delivered the commercial housing to the buyer within the prescribed time? Recently, the People's Court of Wanning City, Hainan Province, tried a dispute over a housing sales contract and ruled that the contract signed by both parties was invalid. The developer should return the purchase price and bear corresponding contractual liability according to the degree of fault. On October 18, 2012, Guo signed a "Contract for the Sale and Purchase of Commercial Housing" with a company in Hainan, which stipulated that the commercial housing purchased by Guo was a pre-sale commercial housing; The area and price of the house have been specified, and the total amount of the house is over 1.03 million yuan; A certain company in Hainan should deliver the commodity house (raw material house) to Guo for use before October 30, 2013, and must go through the engineering completion acceptance filing with the quality supervision department. After the contract was signed, Guo paid an initial purchase price of 500000 yuan, but the commercial housing involved in the case has not been completed and has not yet obtained a pre-sale permit certificate for the commercial housing. Afterwards, Guo filed a lawsuit with the People's Court of Wanning City, demanding that a company in Hainan return the 500000 yuan already paid for the purchase of the house and pay interest during the period of fund occupation. During the trial of this case, after investigation, it was found that the commercial housing project involved was developed and constructed by a company named Xin and a company named Sanya through the signing of the "Contract for Cooperative Development of Hotels and Real Estate" and the "Supplementary Agreement to the Contract for Cooperative Development of Hotels and Real Estate". The land for this project was registered under the name of a company named Xin in Hainan, and the "Contract for Cooperative Development of Hotels and Real Estate" has been recognized as a land use right transfer contract by an effective judgment. A company in Sanya stated that it recognizes the behavior of a company in Hainan and Guo in signing a contract for the sale of commercial housing related to the sale of the property. The Wanning City Court, after trial, found that the commercial housing had not yet obtained the pre-sale permit for commercial housing. In this situation, the seller entered into a commercial housing sales contract with the public to sell the house and collect the payment. According to the principles of ensuring transaction safety and safeguarding public interests, the commercial housing sales contract should be deemed invalid according to law, and the seller should return the purchase price and bear corresponding contractual liability according to the degree of fault. The defendant Hainan Company should return the purchase price of 500000 yuan and the corresponding interest during the period of fund occupation to the plaintiff Guo, and reject the plaintiff Guo's other claims. (New Society)