The rapid development of network technology brings about the expansion of social media on the global scale. Meanwhile, the impact of the social media on the political sphere has been the topic of much debate in recent years. In order to better understand the role of social media in political communication realm, this study offers a step forward by reporting on findings from a cross-national survey of German and Chinese university students that furthers our understanding of how social media as a resource affect their political participation in their daily lives. Rather than simply looking at how much student uses social media, the study contributes to comparative research about what are the different of young people's social media usage between a developing country and development country in terms of their political participation. Besides, the study gives insights into the interplay between social media and traditional media news use in both Germany and China.Results show spending time on social media has no significant influence on young people's political participation in Germany and China. However, certain online activities through social media are clearly and significantly related with political participation in the two countries. There are also significant different level of political participation between Germany and the Chinese college students. Additionally, the results demonstrate that the use of social media news sources is positively associated with different types of political participation. Most interestingly, the study finds that although social media emerges as an important predictor of political engagement in the online domain, it doesn't replace or substitute the role of traditional media in the political communication field. Overall, this study shed a positive light on the ongoing debate regarding the democratic potential of the social media in a different socio-political context. Moreover, the study provide an important step forward by empirically demonstrating that the differences levels of Germany's and Chinese students' democratic engagement from a broader definition of political participation.