The writing's purpose is to investigate the changing sea guard awareness of Chinese by analyzing the treaty between the Qing Dynasty and Western Powers. In other words, it is an attempt to chase developing process of sea guard awareness. This is also a work to know earlier developing process of sea guard awareness for find a origin of current territorial waters conflict. In the body of writing, there is awareness of the Qing Dynasty's sea guard by analysis of domestic and foreign treaties. In result, We found that the cause of highlight of Chinese sea guard is treaties of lease with western powers after the Sino-Japanese War. Especially, awareness of territorial waters became clear in 20th century. In this time, several changes occurred at once, such as overall open of costal territory and new commercial treaty and a growth of awareness of sea territory right. Unlike modern territory awareness in the land, modern territorial awareness in the sea was engraved in the Chinese with accumulation of time and experience.