Abstract: Online marketplaces of mobile applications have undergone dramatic growth in recent years, as exemplified by Apple AppStore and Google Android Market. However, systematical observation and analysis of such a market are still missing. Therefore, this study seeks better understanding of such marketplaces by measuring one of them, i.e., the Google Play Market, from various perspectives. Since this market has grown to a complex system with large amount of applications, this study measures it from the scope of complex networks. To this end, this study first constructs two app relationship networks and one user navigation network based on the data set crawled from the Google Android Market. This study then generates both micro-scope and macro-scope statistics and analysis on various essential metrics of those three networks. By this way, this study is in the purpose of revealing both the relationships among applications and the influences imposed on the user behaviors by the market. To the best of the knowledge, this study is the first to observe, analyze the mobile application market, especially from the view of complex network. Results of this study can serve as data supports for various future researches on mobile apps, which is a rising and problem abundant area in the era of mobile computing.