Abstract: The sea bass (Lateolabrax japonicus),captured from the coastal seas of Xiamen Fujian and Rizhao of Shandong,was sampled for the study.Polyacry lamide gelelect rophoresis was used to detect the expression of isozymes in two tissues,muscle and liver.Altogether,10 isozymes including LDH,MDH,ME,α-GPDH,ADH,SDH,G-6-PDH,EST,GDH were analyzed.Biochemical genetic analysis shows that the 10 isozymes are coded by 19 geneloci,four of which are polymorphic(ME-1,G-6PGH-2,EST-1,EST-5).The percentage of polymorphicloci is 21.1%.Average heterozy gosity of Rizhao stock is 0.111 2,and Xiamen stock 0.093 9.Genetic similarity and genetic distance between two stocks are respectively 0.990 2 and 0.009 8.RAPD method was also used to analyze the genetic diversity of two stocks.The result shows that using the 31 random primers,263 RAPD sites are detected from Rizhao stock,82 of which are genetic polymor phism,the percent age of polymorphic loci is 31.18%.192 RAPD sites are detected in Xiamen stock,46 of which are polymorphic,the percentage of polymorphic loci is 24.08%.The intra-stock genetic similarity between two stocks is 0.833 8,genetic distance 0.166 2.These adequately show that there is a significant genetic variation between two stocks.Specific DNA fingerprints are obtained by primers of S-11,S-42,S-45,S-52 and S-203.8 proper bands are so obviously that might be used as molecular markers for disting uishing the different fries,also providing the genetic foundation for breeding seed high-quality seed and protecting the germplasm resource of L.japonicus.