There are currently several ideas on the table for a climate treaty post-Kyoto. We consider the impact on China of three ideas: a cap on the CO2 intensity, a cap on the CO2 level, and a cap on the CO2 intensity in key sectors. We find that a cap on the CO2 intensity gives large environmental co-benefits to China on aggregate, but there are significant negative effects for rural households. Assuming these are addressed the country could reduce its CO2 intensity by a third before costs outweigh environmental co-benefits. By contrast a cap confined to the manufacturing and power sector does not bring substantial co-benefits to China.