This paper assesses the economy-wide impacts of opening for Mainland Chinese tourists' policy via simulation using GTAP model. It is concluded that 1. the macro-economy will benefit from the increment of real GDP by US$78.656 millions, and the increase of social welfare by US$339.401 millions; and 2. the impacts on individual industries include the production value increase of trade products by US $407.488 millions which is the largest among all the industries, the decrease in other manufactory product value by US$1747.406 millions which is the largest decrease, the decrease in exports to Mainland China by US$558.039 millions which is the largest among all the nations, and the increase in Taiwanese imports mainly due to the increase of imports from EU and USA by US $ 46.642 millions and 44.762 millions, respectively.