The purpose of this paper is to study the legislatures of the Republic of China (Taiwan) and the United States of Mexico. It starts with the development of the parliaments of the two countries, expands the legislative process at various stages, and explains normative items, legal procedures, etc. This paper also explores the structure, organization and power of the parliaments of the two countries, and then details the specific legislative process and the various elements that affect the legislation. There is no relationship between the legislatures of the Republic of China (Taiwan) and the United States of Mexico. Therefore, this study is not a comparative analysis of the similarities and differences between the congresses of the two countries, nor is it an exploration of social phenomena or political issues that may occur in the legislative process of the two countries. This paper reviews the interesting details of the legislative organization, especially for each country, the legislative process is crucial and worth analyzing and exploring.