并存的债务承担是指第三人与债务人共同向同一债权人承担债务,在性质上它不是新债的产生而是债务的一种转债务承担,包括连带责任的并存债务承担和按份责任并存债务承担。债务承担合同的生效同免责的债务承担相同需要债权人的同意,第三人的资历和信用同样重要。在实践中它有着同保证合同的保证作用,但二者有本质区别。第三人享有原债务人对债权人的抗辩权,连带责任第三人和按份责任的第三人享有抗辩权的范围不同,但二者都不能超出原债务人抗辩权范围和内容。 The coexistence of debt commitments refers to the third person and the debtor to the same creditor assume the debt, in nature it is not the generation of new debt but a debt transfer of debt commitments, including co-liability co-exist debt obligations and co-liability coexist bear. The entry into force of a debt contract is the same as the assumption of a debt with a debt. The third person’s qualifications and credit are equally important. In practice, it has the guarantee function of the guarantee contract, but there is an essential difference between the two. The third party enjoys the right of defense of the original debtor against the creditors. The scope of the defaulting rights of the third party who jointly and severally liable and the third party according to the liability have different rights, but both of them can not go beyond the scope and content of the original debtor’s defense.