The United States is the first country that has introduced legislation designed to stimulate orphan drug research and development .In this paper , we analyze three major amendments of the Orphan Drug Act ( ODA) since 1983 and its incentive system .We then discuss the success of the ODA in encouraging orphan drug research and development and boosting the biopharmaceutical industry .Following that , we investigate the high price of orphan drugs caused by market exclusivity and drug repositioning .Finally, we draw experience from the ODA to make some suggestions on how orphan drug legislation can be devised in China with the aim of improving the health of rare -dis-ease patients and facilitating the development of Chinese biopharmaceutical industry .