摘要： 尽管学说上不乏争议，但实务中普遍认为，《合同法》第54条的显失公平制度应遵从《民通意见》第72条，包含主客观双重要件。不承认主观要件，不仅面临教义学上的障碍，在价值层面也难以成立。就规范目的而言，显失公平制度是公序良俗原则之体现，与公平原则或诚信原则并无关联。它的适用对象可以是合同，也可以是合同条款；适用范围不限于双务合同，亦不限于民事交易。在一些情形下，显失公平的判定可以采类似于动态系统论的立场，综合考虑主客观要件。就法律后果而言，变更原则上优先于撤销；变更合同条款时，原则上应模拟当事人真意，不宜直接套用相应的任意性规则。

关键词: 显失公平, 公序良俗, 公平原则, 乘人之危

Abstract: It is widely accepted in the case law that unconscionability,  in spite of the dispute among scholars,  has a substantial and a procedural element. The ignorance of the latter would cause conceptual problems and negative results. The unconscionability doctrine is a materialization of the principle of public policy. It can be applied to bilateral contracts and some unilateral contracts,  and to civil contracts as well as(limitedly)to business contracts. More exactly,  either a contract or a contract term could be unconscionable. In some special circumstances,  unconscionability can be established based on the so-called “bewegliches system” theory,  which allows a “compensation” between the substantial and the procedural element. A modification is always better than a revocation. In case of modifying a contract the court should in principle try to imitate the bargaining between the parties. A modification according to the default rules should be exceptional. The rules on the unconscionability doctrine in the draft of the General Part of Chinese Civil Code is to be improved.

Key words: Unconscionability, Public Policy, Principle of Fairness, Exploitation of the Other Party's Danger, Chinese Civil Code