In order to estimate toxicity of copper, radmium and chromium on survival, growth and oxygen consumption of the estuarine mysid, Neomysis awatschensis, adult and juvenile, the experiments were conducted by renewal bioassay method at $20{pm}1^{circ}C;and;20{pm}1\%_{circ}$ salinity. The $96hr-LC_{50}$ of the mysid exposed to cadmium, copper and chromium was 20.2, 11.3 and $670.4;{mu}g/ell$ in adut and 3.4, 1.9 and $49.4;{mu}g/ell$ in juvenile, respectively, and were ranked in order of toxicity : copper >cadmium >chromium. Survival rates of the mysid exposed to the sublethal concentrations of heavy metals for 40 days were significantly affected by cadmium $geq1.0;{mu}g/ell$ and copper $geq0.6;{mu}g/ell$ concentrations. The growth rate of the mysid exposed to $cadmiumgeq2.0;{mu}gell$ and copper $geq1.2;{mu}g/ell$ concentrations were significantly reduced than that exposed to normal condition, but there was no affect on intermoult period. Oxygen consumption rate of the mysid exposed to heavy metals was significantly reduced with increasing heavy metals concentrations. The results of the present study led us to conclude that concentrations levels cadmium$geq1.0;{mu}gell$ and copper $geq0.6;{mu}gell$ of the estuarine could markedly affect the distribution and population of the mysid by reduced survival, growth and oxygen consumption rate.