The parties to a contract may rescind the contract under any of the following circumstances: (1) It becomes impossible to achieve the purpose of contract for a force majeure. (2) Prior to the expiration of the period of performance, the other party expressly states, or indicates through its conduct, that it will not perform its main obligation. (3) The other party delays performance of its main obligation, and after such performance is demanded, still fails to perform within a reasonable period. (4) The other party delays performance of its obligations, or breaches the contract in some other manner,making it impossible to achieve the purpose of the contract. 有下列情形之一的，当事人可以解除合同： （一）因不可抗力致使不能实现合同目的； （二）在履行期限届满前，当事人一方明确表示或者以自己的行为表明不履行主要债务； （三）当事人一方迟延履行主要债务，经催告后在合理期限内仍未履行； （四）当事人一方迟延履行债务或者有其他违约行为致使不能实现合同目的。