Is the sales contract signed by both parties legally valid if the property ownership certificate is not down
 It is legally valid. With reference to Article 15 of the Property Law of the People's Republic of China, unless otherwise provided by law or agreed in the contract, a contract for the establishment, modification, transfer and termination of the real estate property rights between the parties shall come into force upon the establishment of the contract; Failure to register the real right shall not affect the validity of the contract. With reference to Article 8 of the Contract Law of the People's Republic of China, a legally formed contract is legally binding on the parties. The parties shall perform their obligations in accordance with the contract, and may not modify or terminate the contract without authorization. A lawfully formed contract shall be protected by law. With reference to Article 32 of the Contract Law of the People's Republic of China, if the parties enter into a contract in the form of a letter of contract, the contract is formed when both parties sign or seal it. With reference to Article 35 of the Contract Law of the People's Republic of China, if the parties conclude a contract in the form of a contract, the place where the parties sign or seal the contract is the place where the contract is formed. With reference to Article 107 of the Contract Law of the People's Republic of China, if a party fails to perform its contractual obligations or fails to perform its contractual obligations in accordance with the agreement, it shall be liable for breach of contract by continuing to perform, taking remedial measures or compensating for losses. With reference to Article 10 of the Property Law of the People's Republic of China, real estate registration shall be handled by the registration authority in the place where the real estate is located. The State implements a unified registration system for immovables. The scope, organ and method of unified registration shall be stipulated by laws and administrative regulations. With reference to Article 11 of the Property Law of the People's Republic of China, when applying for registration, the party concerned shall provide the ownership certificate, real estate boundary address, area and other necessary materials according to different registration items. With reference to Article 12 of the Property Law of the People's Republic of China, the registration authority shall perform the following duties: (1) check the ownership certificate and other necessary materials provided by the applicant; （2） Ask the applicant about the registration matters; （3） Register relevant matters truthfully and timely; （4） Other duties stipulated by laws and administrative regulations. Where the relevant information of the real estate applying for registration needs further proof, the registration authority may require the applicant to supplement materials, and may conduct on-site inspection when necessary. With reference to Article 13 of the Property Law of the People's Republic of China, the registration authority shall not commit any of the following acts: (1) require the appraisal of real estate; （2） Repeated registration in the name of annual inspection; （3） Other behaviors beyond the scope of registration responsibilities. With reference to Article 14 of the Property Law of the People's Republic of China, the establishment, change, transfer and extinction of the real estate property right, which shall be registered according to the law, shall come into force when recorded in the real estate register. With reference to Article 20 of the Property Law of the People's Republic of China, the parties to the agreement on the purchase and sale of houses or other real estate property rights can apply to the registration authority for advance notice registration in accordance with the agreement in order to ensure the realization of property rights in the future. After the advance notice registration, if the real estate is disposed of without the consent of the obligee of the advance notice registration, it will not have the effect of biological rights. After the advance notice registration, if the creditor's right is extinguished or no application for registration is made within three months from the date when the real estate registration can be carried out, the advance notice registration shall become invalid. With reference to Article 21 of the Property Law of the People's Republic of China, if a party provides false materials to apply for registration and causes damage to others, it shall be liable for compensation. Where a registration error causes damage to others, the registration organ shall be liable for compensation. After the registration organ makes compensation, it may recover the compensation from the person who caused the registration error. With reference to Article 22 of the Property Law of the People's Republic of China, the real estate registration fee shall be charged on a case by case basis, and shall not be charged on the basis of the area, volume or price proportion of the real estate. The specific charging standards shall be formulated by the relevant departments of the State Council in conjunction with the competent pricing department. In conclusion, the sales contract signed by both parties is legally valid without the property certificate. Do you understand this?