To study the effect of morphometric attributes on body weight of the Steelhead Oncorhynchus mykiss,morphometric measurement was taken from 116 samples.The attributes used in this study include body length,body height,body depth,head length,eye diameter,eye cross and bodyweight.A correlation coefficient matrix was constructed,in which the body weight was used as the dependent variable and other attributes as independent variables for path analysis.The path coefficients,determination coefficients,and correlation index were calculated,and major morphometric attributes were determined.The results showed that all the correlation coefficient between each independent variable and dependent variable (body weight) were significantly different (P<0.01).The trait with the strongest direct effect on body weight was body height (0.363),then the body length (0.291),body depth (0.264) and eye diameter (0.111).The high value of multiple correlation index R² at 0.972 between morphometric attributes and body weight suggests that the selected attributes are practical.The multiple regression equation relating the body weight was established as y=-107.53+3.03 X₁+20.01 X₃+12.63 X2+45.56 X₅,where y is body weight,X₁,X₂,X₃,X₅,is body length,body height,body depth,eye diameter respectively.