If the relationship between fluctuation of CPI and monetary supply is based on the linear regression to study, and it will ignore two questions: 1) the functional relationship is immutable; 2) the effects are symmetry or not. In this paper, we used the non-linear STR model to analyze the nonlinear and asymmetric relationship. This study found that, using logistic function as excessive function of the STR model could well describe the nonlinear and dynamic relationship between CPI fluctuations and the monetary supply. The STR model shows that, during the period from January 1993 to December 2010, between CPI and the monetary supply in China there is a significant asymmetry, with highly non-linear characteristics. Between them lies the dynamics of regime switching. In the regime of tight monetary policy, the fluctuation of CPI is intensified; in the regime of loose monetary policy, the fluctuation of CPI is dominated by market economy.