Abstract: Comprehensive tests on filter geotextiles applied in Shenzhen River are carried out, and the long term permeability, soil retention capacity and clogging of geotextiles are analyzed. The method of strength declining is used to analyze the long term strength of geotextile and geotextile durability. From the tests, the permeability of geotextile declines to few percent,meanwhile, the strength loses about 50 percent and the declining rate is less than 0.26 percent per month. It is indicated by the tests that the permeability and strength declining of geotextiles tend to be stable and the geotextiles meet the demands of filter protection.