By adopting the output effect and price effect model constructed by Karras and applying the vector autoregressive VAR analysis framework, the impact of opening-up on China's interest rate effect was empirically tested. The results show that the impact of interest rate on output effect tends to be less obvious with the increasing openness, and its impact on price effect tends to be amplified with the increasing openness. On the one hand, the government should adjust the interest rate level reasonably according to economic growth to increase output effect; on the other hand, when achieving the economic growth target, the government should set the range of price fluctuation level, so that the price level of our country can be stabilized in a reasonable and controllable range. Keywords: opening-up; interest rate effect; output effect; price effect