由第三人履行的合同刍议

由第三人履行的合同以担保第三人的履行为合同标的，合同的当事人是债权人和债务人，而非第三人。债务人负担的是担保义务，第三人没有履行或履行不符合约定，即属债务人担保义务的违反，发生违约责任。其违约责任原则上为损害赔偿责任，所赔偿者为债权人的履行利益；个别场合也可以是代为实际履行责任。

A Preliminary Study on Contract on the Performance of a Third Party

A contract on the performance of a third party aims at assuring a third party's performance.The promisee and the promisor are the two parties of the contract,and the third party is not a party of it.A duty of the promisor here is to assure or warrant the third party's performance.If there is no performance of the third party or if there is no suitable performance of him,this will constitute a breach of the promisor's warranty duty.Normally the liability of the promisor's breach of his warranty duty is damages,but on some occasion it may be specific performance.