Abstract: The research fits a macro - financial - stability index using PCA method from the angle of macro – prudential regulation and then makes a migration test of influence mechanism of monetary policy on financial stability by STR model. We come to several conclusions through the study: the influence mechanism of monetary policy on financial stability has structurally changed within the period of subprime crisis; there is a prominent positive correlation relationship between monetary policy and macro - financial - stability index , but it appears obviously unsymmetrical before and after financial crisis; after financial crisis, the reaction of financial stability index to monetary policy is more sensitive.

Key words: financial stability; monetary policy; macro - prudential regulation; STR – Model