Relevant research regarding the mechanism through which monetary policy affects the risk-taking level of economic agents, will affect the financial cycle, thus the so-called risk-taking channels, is relatively mature. Distinguished from the traditional studies that focus on monetary policy stance, this paper analyzes monetary policy’s impact on financial cycle through both the quantity-based and the price-based monetary policy reaction function channel and its time-varying mechanism. The rolling regressions find that: 1) both under the quantity-based rules and the price-based rules, monetary policy’s reaction sensitiveness to credit mainly affects the fluctuation of financial cycle, while under the price-based rules, the gap of different effects brought by monetary policy’s reaction sensitiveness to credit and monetary policy’s reaction sensitiveness to credit is small; 2) compared with the situation under the price-based rules, monetary policy’s reaction sensitiveness to credit plays an more important role in influencing the evolution of the financial cycle, under the quantity-based rules, and amplifies gradually. The innovation of this paper lies on the stress on monetary policy reaction function channel which means that monetary policy influences the financial cycle through its reaction function instead of its stance, and the attempt to establish models of it.