Traditional morphological data and truss network data were combined to conduct principal component analysis and stepwise discriminant analysis to study the morphological variations between two populations of Coilia ectenes.The results are showed as follows: morphological variations between these two populations were mainly caused by the distance from most anterior of scales on skull to origin of dorsal fin;discriminant analysis with 25 morphological parameters indicated that there were extremely significant differences between the two populations of Coilia ectenes (P <0.01), the accura-cy is 100%;disrriminant analysis with selected 9 morphological parameters showed that there were extremely significant differences between the two populations of Coilia ectenes (P<0.01), the identification accuracy are 95%-100% (Pl)and 95.2%-100% (P2) respectively, and the synthetic identification accuracy is 97.5%;ANOVA analysis was conducted on the morphological parameters of Coilia ectenes and the coeffieientH of difference of these parameters were also calculated.According to Mayr1 s 75% Rule, this paper reveals that the difference between the two populations of Coilia ectenes belongs to population level, and has not risen to the subspecies level.