Abstract: 268 shrimps of the fifth generation of Litopenaeus vannamei breeding population were collected for measuring the morphometric characteristics, including body weight (W ), body length (X1), carapace length (X2), carapace height (X3), carapace width (X4), the first abdominal segment height (X 5), the first abdominal segment width (X6), the second abdominal segment height (X7), the second abdominal segment width (X 8), the third abdominal segment height (X9), the third abdominal segment width (X10), the sixth abdominal segment height (X11), the sixth abdominal segment width (X12) and telson length (X13). The correlation coefficients, path coefficients and decision coefficients were calculated, and the effects of morphometric characteristics on body weight were analyzed. The results showed that path coefficients of X1, X2, X3 and X4 on body weight were significant (P＜0.01). Body length (X1) had the largest coefficient and was the key effective factor. High determination coefficient (ΣR2=0.9311) between the four morphometric characteristics and body weight indicated that they were the main influencing factors. The regression equations of body length (X 1), carapace length (X2), carapace height(X 3), carapace width (X 4) and body weight(W) were W=0.0136X 12.9559(R 2=0.9642), W=0.7969 X22.4042(R2=0.7360), W=4.712X 32.0628(R 2=0.6373) and W=4.633X 42.1903(R 2=0.6819), respectively. The multiple regression equation for the estimation of body weight wasY =-21.798 2.569X 1 1.104X 2 1.069X 3 0.4231X 4.