First, check the relevant documents carefully. Development projects must obtain land use right certificates, construction land planning permits, construction project planning permits and construction project construction permits; Check whether the developer has obtained the commercial housing sales (pre-sale) license and verify whether the house to be purchased is within the building number listed in the commercial housing sales (pre-sale) license. Second, pay attention to the deposit terms. When buyers buy faster houses, they usually pay a deposit to the developers. According to the guarantee law, the amount of deposit agreed by both parties cannot exceed 20% of the total contract price. Third, distinguish between deposit and advance payment. Fourth, pay attention to the area in the purchase contract. Fifth, pay attention to the force majeure clause in the purchase contract. Delayed delivery is one of the most prominent problems in commercial housing transactions. Developers often use force majeure as an excuse to escape the liability for breach of contract. In order to avoid this loss, the buyer must attach great importance to the relevant clauses related to force majeure when signing the contract. An intransitive verb: the agreement of the developer's property right certificate obligation.