Genetically modified (GM) cotton has been widely adopted in China and the list of GM technologies undergoing trials is impressive. However, when China should commercialize its GM food crops is the subject of debate. The overall goal of this report is to provide an economy-wide assessment of these issues under various scenarios. Our results - which are based on unique data from an empirical micro-level study and field trial in China, and from a modified GTAP model - indicate that the development of biotechnology has had and will continue to have an important impact on China's production, trade and welfare. Welfare gains will far outweigh the public biotechnology research expenditures. Most gains will occur inside China. Therefore, policy makers should put less weight on the international dimension when making their decisions about biotechnology development.