China has devoted considerable resources into developing GM cotton expressing _-endotoxins from the bacterium Bacillus thuringiensis (Bt) to control insect pests. The economic benefit of Bt cotton exceeded US$5.3 billion over the 18 years after it was commercialised. With increasing adoption, target pest populations have been suppressed not only on this crop, but also greatly reduced on other crops in the same area. However, reduced insecticide use led to mirid bug outbreak, indicating that Bt crops must be considered as one component of an integrated pest management programme. With decreased insecticide use, abundance of generalist predators increased, resulting in increasing biocontrol services (such as decreasing aphid abundance) provided by natural enemies. The sustainability of GM crops has been subject to heated debate in China; Bt cotton has proven less controversial, as production, ecological, and human health benefits have been realized and cotton is a non-food product. Empirical evidence that GM technology offers long-term economic benefits, that ecological benefits are realised, and ecological risks can be managed might help resolve public debate, and inform agricultural biotechnology policy in China and other countries.