民事诉讼中的当事人适格是指针对具体的诉讼成为本案的当事人的资格。本文以民事诉讼中的当事人适格为研究对象，主要研究两个问题：一是哪些人具有当事人适格即诉讼主体资格的问题，另一个是当事人适格在整个民事诉讼程序上的地位。本文通过理论梳理和分析、法律规定的整理和解释、实务案例的对比和评说，最终得出结论认为，关于诉讼主体资格的问题，与实体法具有十分紧密的关联并且无论是在理论上还是在实践中都已经基本获得共识，一般就是指争议的民事法律关系的主体，研究价值已经不大；而当事人适格在诉讼中究竟是起诉条件、实体判决前提条件还是实体请求权条件始终处于暧昧不明、争议不断的状况之中，特别是在中国。并且研究该问题对于深刻认识民事诉讼及促进程序的优化有着重要意义，因此理论界应当重新重视当事人适格，但是要把研究重点转移到对其在整个程序中的地位和作用上来。与文章结构相对应，本文采纳了比较的方法、法律解释的方法和案例评析的方法，对与当事人适格有关的理论、法律规定和司法案例进行系统研究。

The qualification of proper parties in civil procedure is about some determinants that make sure parties participating in certain litigation are appropriate. But its significance are more than that. This thesis chooses proper parties in cavil procedure as its major subject, aiming at solving two problems. The first one is, for a specific civil litigation, what kind of person can be recognized as proper party, which is a matter of qualification. The second one is what role does this sort of qualification play in the whole procedure. Focusing on the two problems mentioned above, this thesis consists of summarization and analysis of theories, integration and interpretation of rules, as well as collection and assessment of cases. The final conclusion is, since situations of proper parties have been closely tied to civil law, and theories about the qualification for proper parties has been largely agreed on, which, in principle, means the parties are the right owners and the obligors, it is no longer that meaningful to continue research on this dimension. On the contrary, whether this qualification should be recognized as conditions for suing or conditions for getting final judgments, or just a part of final judgments is a very ambiguous and controversial question, especially in China. In the meantime, research about the role of the qualification can enrich study on civil procedure and make it better designed and changed. Consequently, the theory circle should turn their eyes back to proper parties in civil litigation, however, the emphasis of study should be put on the role of the qualification of proper parties in the whole procedure.Consistent with the structure of this thesis, three kind of research methods have been adopted, that is, comparison, hermeneutics and case analysis, to study the theories, rules and cases on proper parties in civil procedure.