From May to July 2004 and March to April 2005,two fishery resources survey cruises were carried out using trammel net in the adjacent waters area of 23 main Islands and reefs of South China Sea:Lingyang reef,Huaguang reef,Yinli bank,Dong island,Binmei bank,Paihong bank,Bengu shoal,Biwei shoal,Wuyong shoal,Haijiu shoal,Shuangzi reefs,Zhongye reefs,Houteng reef,Meiji reef,Renai reef,Xianbin reef,Nanfang bank,Zong bank,Dayuan bank,Yongshu reef,Nanxun reef,Niue reef and Daoming reefs.A total of 408 Cartilaginous fishes of 33 species from 7 orders and 15 families were caught in the adjacent waters area of 21 main Islands and reefs of South China Sea,except Meiji reef and Nanfang bank.Based on the data,this paper analyzed composition and distribution of Cartilaginous fishes in the adjacent waters area of main Islands and reefs of South China Sea using distribution of species diversity of fishes in systematic order, index of relative importance and catch per unit effort.It can be used as a reference for fishery resources exploitation and management of coral reefs of South China Sea.The results show that Taeniura meyeni,Hexanchus griseus and Carcharhinus limbatus were preponderant species,and CPUE ranged from 73 kg/10~4 m~2 to 499 kg/10~4 m~2 in the Xisha Islands;Taeniura meyeni and Triaenodon obesus were preponderant species,and CPUE ranged from 114 kg/10~4 m~2 to 245 kg/10~4 m~2 in the Zhongsha Islands;Carcharhinus limbatus and Triaenodon obesus were preponderant species,and CPUE ranged from 51 kg/10~4 m~2 to 846 kg/10~4 m~2 in the Nansha Islands except Meiji reef and Nanfang bank.