This paper provides a detailed overview of China's participation in international trade using newly available data on the universe of globally engaged Chinese firms over the 2003-2005 period. We document the distribution of trade flows and product- and trade-partner intensity across both exporting and importing firms and study the relationship between firms' intensive and extensive margins of trade. We also compare trade patterns across firms of different organizational structure, distinguishing between domestic private firms, domestic state-owned firms, foreign-owned firms, and joint ventures. We explore the variation in foreign ownership across sectors, and find results consistent with recent theoretical and empirical work on the role of credit constraints and contractual imperfections in international trade and investment. Finally, we examine the rapid expansion of China's trade over the 2003-2005 period, and decompose it into its extensive and intensive margins. We also use monthly data and study the frequent churning and reallocation of trade flows across firms and across products and trade partners within firms.