This experiment was conducted on the effects of salinity on growth and oxygen metabolism in juvenile Penaeus japonicus. Salinity had significant effects on the growth and survival rate of juveniles. The best salinity for juvenile prawn growth was 10.2-26.9, and the highest growth rate was found in the 20.3 salinity group. The effects of salinity and dissolved oxygen content on instantaneous oxygen consumption rate(V) were significant. V showed good linear relation with dissolved oxygen content.