Horizontal starch gel electrophoresis was used to detect the genetic variation of PGM and GPI in five marine organisms, sea urchin（ Strongylocentrotus intermedius ）, sea cucumber（ Apostichopus japonicus Selenka）, sole （ Cynoglossus semilaevis ）, hard clam （ Meretrix meretrix ） and scallop（ Pecten yessoensis ）. For sea urchin, the PGM showed high expression activity in muscle and mature gonad and the loci number was different in the two tissues, while the activity of GPI was rather low. The isozyme demonstrated the same number of loci in the muscle and intestines of sea cucumber, but their activity was quite different. Two PGM loci and three GPI loci were detected in sole＇ s muscle. For the hard clam adductor, the PGM showed high polymorphism and GPI showed monomorphism. One PGM locus and one GPI locus were detected in adductor muscle of the scallop, indicating the low variation of two enzymes. The genetic parameters and genetic variation of PGM and GPI were analyzed for these marine cultured species in Northern China. The genetic structure and relationship between genetic parameters and economic waits were discussed, which will be important in selective breeding programs.