A lot of problems in Chinese economic system reform have been solved by using the analysis methods in western economics. However, these economic analysis methods are too simple to solve such problems as where Chinese economic system will go. In the past, the traditional philosophy "Change" had often been used to analyze the problems. The paper tries to use this philosophy (especially use "song") to analyze how to construct Chinese public finance system,and to provide some constructive advice. Another aim of this paper is to give a new economic way of analysis.