Abstract: [Objective] This paper aims to study the effects of the morphological traits of 1,2 and 3 years old Triplophysa(Hedinichthys)yarkandensis(Day)individuals on their body mass.[Method]Using correlation analysis,path analysis and multiple linear regression method.[Result]For the 1 year old T.yarkandensis(Day)individuals,the correlation coefficients of body mass with body height,eye diameter,body length,body width,and beard length were 0.540,0.694,0.030,0.286 and-0.170,respectively(P<0.05),and the path coefficients also reached very significant level(P<0.05).Body height,body width and beard length had significant influence on body weight,respectively(P<0.05).The related multiple regression equation was Y=1.510+0.897X4-7.377 X8+0.23 X1+0.32 X5+0.674 X6.For the 2 years old T.yarkandensis(Day)individuals,head length,body height and body width were 0.665,0.551 and 0.224,respectively(P<0.05),and the path coefficients also reached very significant level(P<0.05).Head length had significant influence on body weight,respectively(P<0.05).The related multiple regression equation was Y=-0.605+2.487 X2+1.437 X4+0.393 X5.For the 3 years old T.yarkandensis(Day)individuals,body height,head length,body width and eye diameter were 0.771,0.719,0.604 and 0.189,respectively(P<0.05),and the path coefficients also reached very significant level(P<0.05).Body width and eye diameter had significant influence on body weight,respectively(P <0.01).The related multiple regression equation was Y=-6.640+0.579 X1+1.812 X2+2.782 X5+4.573 X8.[Conclusion]At the different stages of 1,2,3 years old fish,different biological indicators should be used to choose different fish in the breeding of T.yarkandensis(Day).