Blunt snout bream (Megalobrama amblycephala) is a widespread and one of the main aquaculture species in China.In present study,through univariate and multivariate analysis,we compared the external morphology of M.amblycephala from three different locations (Liangzi,Poyang and Yuni Lake).The results from one-way ANOVA and one-way analysis of covariance showed significant differences (P<0.05) in all the morphological parameters among the three populations,except for DRC,CRC,HD,DL,AL,PRPD and ND.We observed two discriminant functions among M.amblycephala from three lakes and these were more accurate between Yuni and Liangzi populations.In the principal component analysis (PCA),three principal components were constructed and the related contribution ratios were 39.78%,22.63% and 6.53%,respectively,with the cumulative contribution ratio of 68.95%.The multivariate analysis indicated that morphological variation between Liangzi and Yuni populations was greater,while Liangzi and Poyang populations were more similar in morphology.According to Mayr’s 75% rule,the differences among these three populations were still within the population level.