Litopenaeus vannamei low salinity stocking was playing an important ro le and developed rapidly in southern parts and coastal areas of China in recent years. The stocking salinity level decreased gradually following the development of theory and techniques, the general level is at 1-8 ppt at present, and the characteristics of L. vannamei growth at the low salinity level had not yet been reported. The studies of the characteristics of L. vannamei growth at low salinity aim to provide more theory bases for desalination stocking. Experimental enclosures(l×b×d: 5 m×5 m×1.6 m) were set up in the shrimp pond, 2000 healthy shrimp larvae with body length(BL) 1 cm were reared for 85 days, the population density was 80 ind·m^-2, water salinity was 6 ppt at early time, 3-4 ppt in the middle term and 2 ppt in final term, with desalination naturally and no water exchange in the course of experiment. The average of water temperature was 29.2-31.6 ℃, dissolved oxygen was 3.9-5.8 mg·L^-1, value of pH was 7.8-8.8 and transparency was 20 cm throughout the experimental period. Data from five enclosures were analyzed and used in this paper.The results show that the a verage of shrimp body length growth rate (BLGR) is 1.398 mm·d^-1（ range at 1.353-1.435 mm·d^-1） and that of the body weight growth rate (BWGR) is 0.169 g·d^-1（the range at 0.156-0.176 g·d^-1），the mean value of final BL and BW is 118.83 mm and 14.37 g, respectively. The results also show a period of 15 days for accommodation in early time, and the first 50 days mainly for BL growth and the final 35 days mostly for BW increase. There is a linear fast growth at 20-35 days for BLG and an accelerated increase at 50-60 days for BWG. As the results express as curve regression, the optimum model of BLG is Quadratic, L=7.843+2.297t-0.0105t²(R²>0.99)，and that of the BWG is Boltzmann， W=16.541+(-0.621-16.541)/(1+e^{(t-54.809)/15.456}(R²>0.99). The relationship between shrimp BL and BW fit to the power model W=aL^b，W=4.9×10^-6L^3.0716 (R²>0.99) (the parameter a value is from 4.9 to 9.0×10^-6，and b is from 2.9495 to 3.0716).