DuringMarchtoMay1998and MaytoJune 1999, twosurveycruises were carried out insevencoral reef waters of Nansha Islands : Zhubi , Nanxun , Dongmen , Meiji , Chigua , Yongshu and Huayang reefs using three fishing methods , namely handlining , longlining and gillnetting. The results show that there are obvious differences in relative abundance of fish resources between different reefs surveyed with respect to the three fishing methods , the highest relative abundance of fish resources for gillnetting being in Yongshu reef , for handlining in Huayangreef,andforlonglininginNanxunreef. Andforgillnettingandhandlining,therearealsovariationsin the relative abundance in different depth waters , the biggest value observed for gillnetting occurring in 11 -30m depth waters , and for handlining in less than 10m. The cause leading to the differences is not primary productivity but ecological conditions, mainly related to reef shape and macroalgal biomass. In addition, the dominant taxonomic groups caught in the reefs surveyed are of manifest discrepancy , and this is directly related to such biotic and abiotic environment factors as size and number of grotto , macroalgal biomass and species and quantity of coral polyp etc.