Driven by Taiwan's investment, the economic and trade relationship between Taiwan and the Mainland China is distinctly characterized by intra-industry trade. Before their access to WTO, the foundation for interaction relationship in economy and trade has taken shape, that is the realistic requirement of the economic development and structure improvement of both sides. Due to the great change of international political and economic background, Taiwan is faced with some realistic issues of the reconfiguration of manufacturing industry and structure improvement. After their access to WTO, the foundation for both sides interaction in economy and trade remains unchanged. Moreover, it is more practical and pressing. Further development of economic and trade relationship with the Mainland of China is the most rational choice for Taiwan of it attempts to promote economic development and realizes structure improvement. It can be predicted that the interaction relationship in economy and trade between Taiwan and the Mainland China will be developed forward under the basic rules of WTO.