Abstract: Space station has great advantages over other spacecrafts.This paper describes in detail its four distinguishing features.The first is crew's entering space station after its ejection,which simplifies the process of development as well as enhances the safety guarantee;the second is the capability of automatic resupply,maintenance and replacement of space-borne equipment;the third is the ability to orbit and operate for a long time, and the final is alterability and extendability of its functions.These fea- tures and advantages indicate fully the important place and role of space station in the future manned spaceflight.