Abstract: With the wide use of unmanned aircraft systems (UAS), the U.S. has gradually formulated a series of rules concerning UAS regulation, and continuously adapted such rules to the development of UAS activities and its regulation demands. In recent years, the U.S. proposed a number of new acts, formulated extensive regulations and documents regarding UAS, in order to specify the rules regarding UAS. This reflected the new trends and development of the U.S. civil UAS legislation, including to establish specific air traffic control body for UAS, improve UAS registration and pilot regulation, strengthen the operation permit and operational rules for UA, detail UAS classification, strengthen privacy protection and so on. The legal regulation of UAS in China lags behind the application of UAS and the development of the industry. The UAS rules and regulation mode in the U.S., as well as the principles of integrating UAS into the national airspace system and ensuring aviation safety while taking into account industrial benefits, can be of inspiration for improving the regulatory regime of UAS in China.