The Chinese Communists did not enact the Criminal Law until they had ruled the Mainland for thirty years. Though this enactment seems quite legalized in terms of form, yet the nature of the Criminal Law enacted by the People's Republic of China is considerably different from that of the democratic countries'. As a result, this writer makes a careful study of the nature of the PROC's Criminal Law in terms of class, tool, policy and controdiction separately.Meanwhile, this paper also states first and then criticizes the most controversial issues of the PROC's Criminal Law: ”the Principle of a Prescribed Punishment for a Specified Crime”, and its developing principles. For example, ”the Principle of Defining a Crime and its Penalty”, ”the Principle of Non-retroactivity”, and ”the Principle of Forbidden Analogy” are individually mentioned and commented on.