Acute and chronic responses to PCB toxicity of Neomysis awatschensis were studied by measurement of bioassay, growth, oxygen consumption and nitrogen excretion with concentrations of PCB at 10 and $20^{circ}C$. 96 hr.-$LC_50$ at 10 and $20^{circ}C$ were 28.7492 pub and 10.6742 pub, respectively. Survival rates during 60 days exposured to chronic PCB concentrations of 0.5 pub, 1.0 pub, 1.5 pub and 2,0 pub at $10^{circ}C$ were $85\%,;80\%,;75\%$ and $75\%$, respectively and suwival rates at $20^{circ}C$ $85\%,;75\%,;75\%$ and $65\%$, respectively. Average daily growth rate of N. awatschensis exposed to chronic PCB concentrations at $10^{circ}C$ were 0.039 mm/day in control group and 0.036 mm/day at concentration of 2.0 ppb, while their rates at $20^{circ}C$ showed 0.072 mm/day in central group and 0.039 mm/day at 2,0 ppb. The growth factors were some similarities between the chronic PCB concentrations, but intermolt periods were related to body size of mysids, temperature and PCB toxicity. Changes in oxygen consumption and nitrogen excretion rates during 60 days exposure to PCB toxicity showed higher in high groups of PCB concentrations. Assimilation and feeding rates of N. awatschensis fed Artemia sp. decreased with increase of PCB concentration at 10 and $20^{circ}C$.