罪刑法定原则的确立,使讨论其内涵成为必要,为全面理解它。本文讨论了其刑法,刑事诉讼法、宪法、法理、犯罪学含义。另一方面.罪刑法定原则的确立,对刑法自身的生命力与刑事诉讼法产生了重大影响,为此,文章讨论了刑法的社会适应性及与罪刑法定原则紧密联系的无罪推定原则。 The establishment of the principle of legality of crime and punishment makes it necessary to discuss its connotation and to fully understand it. This article discusses its criminal law, criminal procedure law, constitution, jurisprudence and criminology. On the other hand, the establishment of the principle of legality of crimes and penalties has a significant impact on the vitality of criminal law itself and the criminal procedure law. Therefore, the article discusses the social adaptability of criminal law and the principle of innocent presumption of innocence closely linked with the statutory principle.