Abstract: The thesis sets up a theoretical system of distribution of burden of proof in civil procedure, theoretically on the basis of norm theory, supplemented by modified norm theory, and theories of probability, danger field, danger increase, variety principle and interest balance, according to the law rules of Chinese mainland. The theoretical system includes two parts, namely, general rule and special rules. In terms of the general rule, in civil suits, parties should prove different material facts according to different claims. And in terms of special rules, transformation of burden of proof and special rules of proof evaluation modify the general rule in order to reduce the difficulty of proof.