Due to the severity of the 2008 financial crisis, the Federal Reserves of the United States aggressively lowered policy rate to zero and adopted several "unconventional" monetary policies, including "Quantitative Easing". Literatures have long suggested that US monetary policies had strong spillover effects on foreign countries. The results show that indeed US monetary policies exert significant impacts on the Taiwanese economy. We also discuss the Taiwan's central bank's responses to these spillover effects. This study finds that the U.S. 10-year bond yield has no direct impact on the Taiwan exchange rate market. The reason is that the domestic interest rate is higher than the United States, it attracts investors to transfer funds, which makes the domestic foreign exchange reserves increase and the Taiwan dollar appreciates. Therefore, foreign exchange reserves play a very important role during the Quantitative easing (QE) policy. In addition, the central bank has no significant influence on the intervention of the exchange rate market. The result is different from our general perception. I conjecture that although the central bank adjusts to stabilize the exchange rate, it is still impossible to eliminate the extra excess supply, so that the intervention did not achieve the expect effect.