Related Rule
Practice Relating to Rule 101. The Principle of Legality
China’s Criminal Law (1979), as amended in 1997, states:
Article 3 For acts that are explicitly defined as criminal acts in law, the offenders shall be convicted and punished in accordance with law; otherwise, they shall not be convicted or punished.
Article 9 This Law shall be applicable to crimes which are stipulated in international treaties concluded or acceded to by the People’s Republic of China and over which the People’s Republic of China exercises criminal jurisdiction within the scope of obligations, prescribed in these treaties, it agrees to perform.
Article 12 If an act committed after the founding of the People’s Republic of China and before the entry into force of this Law was not deemed a crime under the laws at the time, those laws shall apply. If the act was deemed a crime under the laws in force at the time and is subject to prosecution under the provisions of Section 8, Chapter IV [which deals with limitation periods] of the General Provisions of this Law, criminal responsibility shall be investigated in accordance with those laws. However, if according to this Law the act is not deemed a crime or is subject to a lighter punishment, this Law shall apply.
Before the entry into force of this Law, any judgment that has been made and has become effective according to the laws at the time shall remain valid. 
China, Criminal Law, 1979, as amended in 1997, Articles 3, 9 and 12.