The Criminal Custom Study Under Context Of Principle Of Legality

'Exclusion of customary law'is an imperative part in the criminal legal system which derives from the principle of legality. As a contrary legal area to this principle,'criminal custom'which rooted from folk customs has been marginalized for long time. From many perspectives, customary law been has ruled because the validity of the principle of legality. On one hand, the theory basis of this principle does not allow the existence of customary law. On the other hand, its extension principles, including principles that reveal its substance and the principles that manifest its characters, also exclude effectiveness of the customary law. Although criminal custom has been rejected by traditional criminal legal theory, its existed function in minority areas could not been ignored. Especially in ethnic minority areas of China, criminal custom plays an important role not only in people's daily life but in judicial practices. Its influence could be found in different scenarios when criminal cases are in processing, such as settling criminal disputes by'civil mediation', avoiding investigation by public security organs and dismissing prosecution by the Court. Actually, the conflicts resulting from diverse roles of criminal custom in legal theory and practices could be reconciled through classifying different types of these customs, mainly including the custom that prefer un-guilty presumption and light punishments and the custom that prefer guilty presumption and serve punishments. The author holds that only the former one could be carefully adopted when the criminal cases are needed to be solved. Meanwhile, different treatments of various criminal customs are also the hint to handle the relationship between customary law and the statutory law.