Recently, the People's Court of Haidian District, Beijing, heard a case of dispute over a house sales contract. Because the house was the joint property of the husband and wife at the time of the transaction, and the interests of the husband and wife were infringed without the consent of the spouse, the sales contract was ruled invalid. The plaintiff Ms. Zhou and Mr. Zhang were originally married. In 2008, the two parties purchased the house involved during the marriage relationship. In the second half of 2014, Mr. Zhang told Ms. Zhou that he wanted to rent the house involved to Mr. Yang and Ms. Xin. Although Ms. Zhou strongly opposed it, Mr. Zhang insisted on delivering the house door card and key to Mr. Yang and Ms. Xin. In 2020, Ms. Zhou and Mr. Zhang divorced and agreed that the house involved in the case should be owned by Ms. Zhou and the house loan should be repaid by Ms. Zhou. Ms. Zhou proposed to Mr. Yang and Ms. Xin to take back the house, but she was refused. At this time, Ms. Zhou learned that, without her knowledge, Mr. Zhang and Mr. Yang signed a house sales contract in 2016 to sell the house to Mr. Yang for 5.5 million yuan, and the selling price was far lower than the market price of the house at that time. Ms. Zhou believed that when Mr. Zhang signed the house sales contract, the house involved was the joint property of her husband and Mr. Zhang, and Mr. Zhang had no right to sell the house. The negotiation between the two parties failed, so Ms. Zhou brought Mr. Zhang, Mr. Yang and Ms. Xin to the court. The defendants, Mr. Yang and Ms. Xin, argued that in June 2014, their couple and Mr. Zhang and Ms. Zhou entered into a house sales contract orally, agreeing to sell the house in the name of Mr. Zhang and Ms. Zhou to them, with the purchase price of 5.5 million yuan. In the month when the oral agreement was reached, Mr. Zhang and Ms. Zhou delivered the house to them. The house has always been occupied by their husband and wife, and the relevant expenses have always been paid by their husband and wife. On July 5, 2014, Mr. Yang paid 3 million yuan for house purchase by transfer. On April 24, 2016, Mr. Zhang and Mr. Yang signed the Beijing Stock Housing Sales Contract. On June 30, 2016, Mr. Yang paid another 2 million yuan for house purchase by transfer. When the house purchase and sale contract was reached orally, Mr. Zhang and Ms. Zhou told them that the loan of the house involved had not been repaid, and Mr. Zhang and Ms. Zhou wanted to use the school district quota of the house, so they did not pay the remaining 500000 yuan for the purchase of the house and did not urge the house transfer procedures. Now it believes that the housing sales contract is the expression of the true intention of all parties, and it does not violate the mandatory provisions of laws and administrative regulations, and should be a valid contract, so it does not agree with Ms. Zhou's lawsuit request. During the trial of the case, Mr. Zhang said that he did not tell Ms. Zhou about the sale of the house. He asked Mr. Yang's uncle for help, so he sold the house to Mr. Yang, knowing that the transaction price of the house was low. At the same time, according to Ms. Zhou's application, the court entrusted the real estate appraisal company to evaluate the market value of the house involved on June 15, 2014, and the appraisal price was 9.52 million yuan. After the trial, the court held that Mr. Zhang and Mr. Yang were the signatories of the Beijing Stock Housing Sales Contract in the case, and Ms. Xin clearly acknowledged Mr. Yang's signing of the contract in the trial. If Mr. Yang and Ms. Xin failed to provide sufficient and effective evidence to prove that they had reached an oral agreement with Mr. Zhang and Ms. Zhou on the purchase of the house, the contract should be recognized as Mr. Zhang and Mr. Yang and Ms. Xin