Nitrogen fertilizer has been excessively used in China's crop production, resulting in large environmental impacts on the atmosphere and water systems. To assess these environmental problems, JIRCAS has conducted a collaborative research project from 1997 to 2004, entitled “Evaluation and development of methods for sustainable agriculture and environmental conservation”. The research was carried out in three intensive agriculture regions, i.e., Huan-Huai-Hai plain, Taihu catchments, and southern red soil area. Field experiments and monitoring identified croplands to be a major source of nitrogen loads to the environment at all the regions. Especially, large amounts of ammonia volatilization equivalent to more than one third of the rate of fertilized nitrogen were detected both at the paddy and upland fields. As options to reduce nitrogen losses from croplands without yield penalty, use of controlled release fertilizer, animal manure, and deep placement of fertilizer are recommended. These options are expected to contribute to reduce environmental impacts of Chinese agriculture, coping with a new direction in Chinese policy for “green society” that was recently incorporated in the 13th Five Year Plan of the government