The Criminal Procedure Act is the procedure norm which regulate concrete realization of the national penal power, which is the national public power that involving the intervention of people's fundamental rights, so that it should comply with Due Process of Law under the Constitutional Law. The operation of criminal procedure essentially is the national penal power, which will violate or restrict people's fundamental rights. It should be properly regulate these national public power based on the constitutional guarantee of Due Process of Law. This article intends to inspect these fundamental principles of Criminal Procedure Law throughout the protection of Due Process of Law to highlight the framework of Criminal Procedure Law, and inspect its actual content , hoping to give prospect on the system of Criminal Procedure Law.