Diversity is one of the key issues in communications policy. This study used the analysis of assessing the exposure diversity of the TV audience. Our study analyzed the 2003-2007 Nielsen and CSM People Meter TV ratings data for Taiwan and China. The study compared the media performance of Taiwan and China in the following three dimensions program-type supply, demand, and bias rate. The program-type supply contained programs that are available in the market. The study measured demand by examining the rating of the different programs. The researcher analyzed the differences between supply and demand to determine the bias rate. Taiwan and China developed different broadcasting policies and media performance during the fifty years of their separation due to diverse political and economic views. This study finds that the effectiveness of the policies do have an impact on content diversity.