行政契约在学理上共有三种模式:行政机关与行政相对人之间签订的契约、行政机关之间签订的契约以及行政相对人之间签订对社会公共利益有影响的契约。本文只讨论第一种常规模式的行政契约,此类行政契约具备契约性和行政性双重属性的行政行为。本文结合私法中关于缔约过失责任的相关理论知识以及行政契约与其他契约相比所具有的双重属性(即契约型和行政性),提出了将缔约过失责任引入到行政契约中的合理性,在此基础上提炼出了行政契约缔约过失责任的概念。以此为基点,概括出行政契约缔约过失责任的特点和构成要件,并在此基础上提出了缔约过失责任在行政契约中适用的责任承担与私法中责任承担的不同即责任主体、责任内容和责任方式,尤其是对责任方式部分,提出:行政契约作为一种行政行为,因此需要受到信赖保护原则的支配。在传统行政法上,认为信赖保护原则是一种行政相对人对授益性的行政行为的信赖利益,但是结合行政契约的特点,本文认为行政契约中的信赖保护原则应当包括行政主体的利益,再根据行政相对人导致缔约过失的心态(故意和过失),分别应当实行行政处罚和强制执行的方式。 There are three modes of administrative contract in theory: the contract signed between the administrative organ and the administrative counterpart, the contract signed between the administrative organs, and the contract signed between the administrative counterparts that have an impact on the social public interest. This article only discusses the first conventional mode of administrative contract, such administrative contract has the contractual and administrative dual attributes of administrative behavior. Combining with the relevant theoretical knowledge of contracting negligence in private law and the double attributes (ie contractual and administrative) of administrative contracting as compared with other contracting, this article puts forward the rationality of introducing contracting negligence into administrative contract, Based on this, the concept of fault liability of contracting of contract in administrative contract is drawn. Based on this, the characteristics and constitutional elements of the liability for contracting fault in the administrative contract are summarized. Based on this, the author proposes the differences between the responsibilities assumed in the contract of contracting and those assumed in the private law, ie the main body of responsibility, the content of responsibility and The responsibility mode, especially the part of the responsibility mode, proposes that the administrative contract should be subject to the principle of trust protection as an administrative act. In the traditional administrative law, the principle of trust protection is considered as a trust benefit of the administrative counterpart to the beneficial administrative behavior. However, in light of the characteristics of the administrative contract, this paper argues that the principle of trust protection in the administrative contract should include the interests of the administrative body, In accordance with the state of mind (intentional and negligent) of negligence of contracting parties caused by the counterpart of the administration, administrative punishments and enforcement measures should be implemented respectively.