Abstract:The evolution from customs into laws must follow either of the two paths : adoption, which includes the process of repetition and adaptation, and transformation, which includes the process of editing and integration. At the same time, the polarization of social order enforced by two different systems of rules is the natural result of the laws' different expressions in these two different systems. Five characteristics, i. e. , progressiveness of process, mutuality of advancement, multiplicity of manners, divergence of degree, and expansion of scope, are put forward in analyzing the evolution of customs into laws.