Abstract: By applying the eventstudy method and floating windows， this study classifies commercial banks into largescale ones and small and mediumsized ones. By analyzing the market reaction of bank stock returns to reserve rate adjustment， the market expectations and the asymmetric effects of reserve rate increasing and decreasing after the financial crisis， whether commercial banks are liable for reserve requirement tax is explored. The findings indicate that reserve requirement tax is assumed by bank stockholders， particularly to largescale commercial banks. Moreover， the market could predict the coming of reserve rate adjustment policies， and to commercial banks an increase in reserve rate has more significant impact than a decrease. Finally， some policy implications are put forward.

Key words: bank stock, reserve rate, market reaction, reserve requirement tax