长期以来，我国宪法学的主流理论认为，全国人大常委会是我国的宪法审查机关，它根据宪法第67条第（1）项的授权，排他性地从事宪法解释活动，或至多承认全国人大自身的宪法解释权。这样的思维遮蔽了一个事实：无论一国的立法机关是否是宪法审查机关，无论它是否获得宪法的明文授权，其职权的行使都具备宪法解释的功能，即实际上从事一种“功能”意义上的宪法解释活动。 立法机关行使职权的行为之所以在功能意义上具备宪法解释的属性，是因为其在行使职权时必然隐含地形成宪法上的判断，而这便是宪法解释的核心要素。考察国内外立法机关运作的实践，可发现，围绕宪法判断的形成这一要素，立法机关通过各种直接或间接的形式解释宪法。 立法机关的宪法解释在内容方面主要体现为立法与宪法规范之间的关系。其中，立法与基本权利规范之间的关系并不仅仅是限制自由权、保障社会权那么简单，而是复杂且多元的；立法与国家机构规范之间的关系，则包括对有关立法机关自身运作的宪法规范以及对有关其他国家机关运作的宪法规范加以解释。 在解释方法方面，立法机关采取的主要是实质的宪法解释方法，即认定立法事实以及衡量相冲突的法益，这也是晚近宪法审查机关所倚重的宪法解释方法。立法机关的某些组织和程序上的制度特征可以支持其采取此种解释方法。 当然，立法机关行使职权的行为在功能层面具备宪法解释的属性，不意味着它可以代替宪法审查活动。对于两者之间的关系，域外存在宪法审查机关至上、立法机关至上以及部门主义三种理解。在存在典型的宪法审查制度、尤其是司法审查制度的国家，从宪法解释的实践当中能够解读出宪法审查机关至上以及部门主义的意味，而立法机关至上则只是一种理论主张。就我国而言，从宪法文本角度分析，若由全国人大常委会从事宪法审查，则应采取宪法审查机关至上模式；若由全国人大及其常委会之外的机关从事宪法审查，则应采取立法机关至上模式。 对域外立法机关的宪法解释功能的系统研究，提示我们不应将宪法解释视作这些国家的法院所独占的事务，而这对我国的启发在于，应致力于构建富有实效性的宪法审查机制，从而在认可立法机关的宪法解释功能的同时，实现宪法解释权的分散化配置。此外，探讨立法机关的宪法解释功能，有助于认识立法与宪法之间的紧密关联，从而重视相关立法制度的完善，在合宪性层面提升立法的质量。

For a long time, the Chinese constitutional theory considers that the Standing Committee of the People’s Congress, based on Item (1), Article 67 of the Constitution, interprets the Constitution exclusively, or recognizes at most the power of the People’s Congress to interpret the Constitution. Such thinking has veiled the fact that the legislature of a country, no matter whether it is a constitutional review authority or whether it obtains the clear authorization from the Constitution, functions as a constitutional interpreter when exercising its power, that is, engages in constitutional interpretation in a “functional” sense. The reason why the exertion of legislative power possesses the nature of constitutional interpretation in a functional sense lies in that the exercising of its power inevitably entails constitutional judgments, which is the core element of constitutional interpretation. It could be found, when observing the practice of both domestic and foreign legislatures, that legislatures, involving constitutional judgments, interpret the constitutions with a variety of direct and indirect means. The content of the constitutional interpretation of legislature mainly embedded in the relationship between law and the constitution. The relationship between law and basic rights norms is not as simple as restricting freedom rights and ensuring social rights, but is complicated and of pluralism; the relationship between law and the norms of the organization and operation of state institutions includes interpretations on the norms of the operation of legislature itself and of other state agencies. Legislature mainly adopts substantial methodology of interpretation, namely, to find legislative fact and balance the conflicting legal interests, which is also the main interpretive method employed by constitutional review institutions recently. Some organizational as well as procedural institutional features of legislature support such interpretive method. Of course, the fact that legislature’s exertion of its power embodies the nature of constitutional interpretation in a functional sense does not mean that it could replace constitutional review. The relationship between these two mechanisms has divided into constitutional review supremacy, legislative supremacy and departmentalism in foreign countries. In the countries where typical constitutional review mechanism, especially judicial review institution exists, the implication of constitutional review supremacy and departmentalism could be understood from the practice of constitutional interpretation, while legislative supremacy remains a theoretical proposition. Under the Chinese situation, from the aspect of the constitutional text, if taking the Standing Committee of the People’s Congress as the constitutional review authority, the mode of constitutional review supremacy should be accepted; while the mode of legislative supremacy should be adopted if taking an agency other than the People’s Congress and its Standing Committee as the constitutional review authority. The systematic study on the function of constitutional interpretation of foreign legislatures prompts that it is improper to deem constitutional interpretation as the exclusive affair of the courts, which inspires that in China, effective constitutional review institution should be constructed, and accordingly, the decentralization of the power to interpret the Constitution could be achieved while recognizing the function of constitutional interpretation of legislature. In addition, it contributes to acquire the close relationship between legislation and the constitution when discussing the function of constitutional interpretation of foreign legislature, as well as to value the consummation of relative legislative mechanism, which might promote the constitutional quality of legislation.