Abstract: Analysing the nonlinearity of Taylor rules by constructing time-varying parameters smooth transition regression model based on theoretical analysis of nonlinear mechanism of monetary policy rules，the results show that policy rules call for changes in nominal rate in response to different zones of inflation. At the same time there is obvious structural transf-ormation in China's central bank's interest rate rules，the coefficient of the nominal interest rate on inflation gap is not signif-icant，because China's central bank's preference is "Zone-like" and asymmetric，but the coefficient of nominal rate on out-put gap is significant，this means the central bank is more focused on the fluctuation of the output gap，and this will be the "new normal" of the central bank's monetary policy operation in the future．

Key words: Taylor rules;nonlinearity; TV-STR; new normal