In order to study the effects of main morphological traits on body weight in Taimen (Hucho taimen), a total of 710 individuals (240 individuals of 3 month old, 180 individuals of 6 month old, 110 individuals of 12 month old, 90 individuals of 18 month old, 90 individuals of 36 month old) were randomly sampled for measuring the metric traits, including the body weight y, body length x1, body height x2, body depth x3, head length x4, eye diameter x5, caudal fin length x6, caudal fin height x7, caudal peduncle height x8. In order to study the effects of metric traits on body weight, the correlation analysis, path analysis and determination coefficients were calculated and multivariate regression equations were obtained. The results showed that the variation coefficient of bodyweight in different months old Taimen was the greatest, which could be achieved 25.52%, 17.92%, 24.99%, 18.45%, 13.03%, respectively (Table 1). The correlation coefficients between morphological traits and body weight were range from 0.017 to 0.963 (Table 2). The normality test results indicated that the 5 groups of samples data were considered as belonging to Gauss distribution by Shapiro-Wilk test and non-obvious discrimination by ANOVA (P > 0.05) (Table 3). As shown in Table 4, body length was the most important trait affected the body weight of 3, 6, 18 and 36 months old Taimen, and the body width was the most important trait affected the body weight of 12 months old Taimen. The results of determinant coefficients were consistent with that of path analysis (Table 5). The multiple regression equations were established as y3 =﹣14.911 + 1.561 x1 + 3.448 x2 + 5.232 x3 in 3-month-old Taimen, y6 =﹣70.321 + 5.192 x1 + 0.962 x2 + 0.473 x3 in 6-month-old Taimen, y12=﹣217.446 + 7.129 x1 + 23.147 x2 + 44.055 x3 in 12-month-old taimen, y18 =﹣891.041 + 20.234 x1 + 65.786 x2 + 53.266 x3 in 18-month-old Taimen, y36=﹣5748.099 + 88.187 x1 + 301.984 x2 + 66.702 x7 in 36-month-old Taimen, respectively. Above conclusions could provide important references and foundations for the selective breeding of taimen.