To elucidate the morphological variation of bighead carp(Aristichthys nobilis) fed by feedstuff, 31 morphological proportional characters for four populations(56 specimens) from four treatments as fertilization(group A), fertilization+ 1/2 feeding(group B), fertilization+ feeding(group C) and feeding(group D) were investigated, using the traditional morphological(one-way analysis of variance, cluster analysis, principal component analysis, and discriminant analysis) and truss network analysis. The four populations of bighead carp differed significantly for 24 morphological proportional characters(e.g., TL/BL, BH/BL, SL/BL), while there were no differences for other characters as HH/BL, HL/BL, 4-6/BL, 5-6/BL between different groups. A cluster analysis indicated that the group B, group C and group D were more similar compared to group A. The principal component analysis yielded seven principal components with a cumulative contribution ratio of 94.6%. The scatter diagram of major principal components also showed group A completely separated from other three groups, while the latter overlapped together. The discriminant functions of the four populations of bighead carp were established based on 6 morphological characters that differed significantly among the populations. The accuracy of discrimination from four populations was 92.7%, 87.5%, 64.3% and 87.5%, respectively, indicating the reliability of discriminant functions. In summary, the morphological characteristics of bighead carp fed feedstuff changed significantly. However, the morphological characters of fish head have not changed, while the trunk from head to the dorsal fin is significantly increased, hence giving an illusion of smaller head. It is the first study to prove the bighead carp fed feedstuff still have the big head features, laying the theoretical foundation for rearing bighead carp with feedstuff.