Study on growth rate and survival rate of polyculture Oreochromisniloticus with Litopenaeusvannmei in different stocking densities in low salinity water.There are four experimental groups. The control group was only one type of tilapia (25./ barrel) and the experiment of Oreochromis niloticus 25 /barrel. With the Pacific white shrimp (Litopenaeus vannamei), and (25 35 45 /barrel). The three replications. The 5 ppt salinity in fiber glass tank size size 500 l rearing period 60 days. The results showed that the survival rate of the shrimp in the experiment. , and (25 35 45 /barrel) survival rate equals 55.25±12.90 percent 50.10±6.18 percent and 45.18±9.12 percent .Which no significant differences in training and in each group experiment (P > 0.05), this study showed that the release rate of tilapia and shrimp both proper. From this experiment is to leave the fish in density 25 / and shrimp vannamei in density 25 / barrel