Abstract: The new method of plasticity based on e-p curv e has obvious advantage over the current method.For example,its solving procedure is more concise than that of the classical theory method. Analytical solutions to many problems c an be obtained by the use of the new method, while they can not be gotten with t he classical theory method. Some important progresses have been made based on th e new method. To show its reasonableness, physical explanation of the new method is given in this paper.