Abstract: By using the vertical polyacrylamide gel electrophoresis,18 loci of 13 enzymes o f neotenous Neosalanx oligodontis are studied.The heat inactivation of LDH has b een studied. The expressions of neotenous characteristics have been observed in ADH,GOT, α-GPDH,LDH,MDH,ME,POX and SOD.Among them LDH is coded with A and B loci,and C l ocus is not expressed,probably resulting from the neoteny occurred at early stag e of development when the LDH C gene had not been expressed.No expressions of ne otenous characteristics have been observed in ES and IDH. α-AMY,CAT and FUM are not analysed on account of the unreliable score.

Key words: Ontogeny, Neoteny, Isozymes, Salangidae