The protection of constitutional human right and the Constitutional reform are highly correlated, among which the construction and implement of the citizenship plays a pre-eminent role in particular. Besides, the inauguration of the citizenship system is based on the status-connection between the state and people, and further involves the definition of the concept of citizen and its acquisition. In the light of the other legal systems, ”nationality” is the most significant symbol to identify a citizen, and an universal system of status-connection between the state and the people. However, what is the rationale on which this hinge relation bases? Concisely speaking, what is the genuine meaning of so called ”nationality”? Is the status-connection created by the law per se? Or are there some pre-exist rationales behind these legal norms? The aforesaid issues are the core problems that this article focuses on. This article, in structure is constituted from nowadays to past, and legal norms before nomological. It refers to present effective laws to find out the distinctions within nationality, residential registration, and foreign resident to reach to the definition in practical matters and explanation. Furthermore, this article is also bodied with the historical track to study the reasons of producing those laws and progression, and with the study to research the nomological relation between the people and the state to deal with the evolution of the nationality of Taiwanese. Finally, it sums up with the correlate topics arising from the problem of nationality, such as the national identity, sovereignty of state, and citizen consciousness.