In recent years, the relationship of mainland China and Taiwan has developed through the increasing economic exchanges. After ECFA (Economic Cooperation Framework Agreement, 2010), the signing of the Cross-Strait Service Trade Agreement attracted highly attention of the media from both mainland China and Taiwan, especially the media represent the Blue Camp and Green Camp in Taiwan area. Grounded on the framing theory, this study applies the content analysis as the research method to explore how the media of mainland, Blue Camp and Green Camp covered the issue differently. Three mainstream newspapers in mainland China (People’s Daily, Economic Daily and Strait Guides) and three newspapers in Taiwan (Liberty Times, United Daily News and China Times) are selected as the subjects of the study. It is discovered that, when reporting the cross-Strait issue, newspapers in mainland China and Taiwan would apply different frames. Besides, within Taiwan area, the newspaper represents Green Camp is more likely to politicalize the cross-Strait issue. The result shows that ideology is one of the significant factors that influence the frames for it not only influence the frame adoption, but also greatly impact the politicalization of a certain issue.