With Litopenaeus vannamei of (2.089±0.021)cm long kept in a 15L polythene circular bucket at 26℃and two factors set: density of 400 shrimps/m3 and 800 shrimps/m3 and five water exchange conditions (no exchange, daily water exchange volume 20%, daily water exchange volume 50%, full water exchange after 3d and full water exchange after 5d), effects of various culturing densities and daily water exchange conditions on water quality and growth of juvenile Litopenaeus vannamei were studied, and regression model of the pollution indexes with culturing density, daily water exchange volume and culturing days was established based on effects of culturing density, daily water exchange volume and culturing days on self-pollution factors. The results showed that culturing density and daily water exchange volume had no significant influence on pH of the water (P>0.05); the concentration of NO2--N , NH4+- N and COD was decreased with the increase of water exchange volume, where the cumulated amount when the daily water exchange volume was 50% was the minimum, significantly lower than that of other groups (P<0.05); in groups of full water exchange after 3d and full water exchange after 5d, the concentration of NO2--N , NH4+- N and COD reached the peak before water exchange dropped to the minimum in the next day, and then gradually increased, which, though repeating in this cycle, was still lower than the control group. Under the same water exchange condition, the self-pollution factor concentration for density of 400 shrimps/m3 was lower than that for 800 shrimps/m3; the regression models of concentration indexes NO2--N (Y1), NH4+- N (Y2) and COD (Y3) with culturing density (X1), daily water exchange volume (X2) and culturing days (X3) were respectively: Y1=0.048-0.002X2-0.001X3, Y2=0.163+0.04X1- 0.018X2+ 0.01X3, Y3 = 4.85+0.429X1-0.199X2. The study indicates that the minimum degree of self-pollution and good growth of Litopenaeus vannamei can be guaranteed at culturing density of 400 shrimps/m3 and water exchange rate of 50%.