摘 要： 由效力未（待）定合同制度与可变更可撤销合同制度共同组成的非完全效力合同制度在我国于上世纪末颁布的新《合同法》中首次得到了确立。该项制度的确立，有益于更好地维护社会交易秩序、促进市场交易规则的完善。本文通过对于参与构建这一法律制度体系的《合同法》及其司法解释、《民法通则》及其司法解释中相关条款的解析，较为全面地阐述了该体系的总体架构，并在此基础上着重论述了其中一些尚有待完善的地方，包括：效力未定合同制度中撤销权设置的合理性、催告对象的确定、设立效力未定期限的必要性以及可变更撤销合同制度中重大误解的界定、选择变更权的缺陷、更合理地设置除斥期间等。由于该项制度中的很多规则是首次在我国被确立，作者在论述的过程中也渗入了一些比较法学的分析方法。 关键词: 合同的效力 效力未定合同 可撤销合同 可变更合同 abstract : it is in the contract law of prc which was promulgated in the end of last century that the legal system of incompletely-effected contract which consists of the legal system of the indefinitely-effected contract and the legal system of the rescissible contract the has been established really and firstly in china. the establishment of this legal system can be propitious to consummate the rule and the development of exchange in nowaday china . basing on the commentating on these articles both of the contract law together with its statutory construction and civil law of prc together with its statutory construction which are the main proportions of the legal system, the paper gives out the configuration of the legal system, and focuses on the imperfect part of the system such as the time limit of the indefinitely-effected contract, the right of contract to alter, the right of contract to rescind etc.. as many of these regulations of the legal system were founded firstly, the author wrote the paper with some analytical methods by which are used in comparative jurisprudence. 关键词: the effect of contract, the indefinitely-effected contract,