Abstract: There were morphological differences among specimens of Garra imberba from Yangtze River,Red River and Langcang River,China.In order to confirm whether the morphologic differentiation have occured among geographical populations,two hundred and fourty-eight specimens of Garra imberba from thirty-two sampling locations were divided into four groups according to drainages stated above,they're Jinsha River,Langcang River,Yuanjiang River and Lixian River.For comparing their morphologic differentiation,external morphological characteristics and meristic characters were observed,eighteen general and seventeen frame characteristics were measured and analyzed by the methods for multivariate morphometrics.The results of external morphological comparation showed that the head and disco shape had some differentiation between specimens from Jinsha River and the other three groups.Comparison of meristic characters indicated that there were no obvious morphologic differentiation among the four groups.Based on the results of scatter plots by principal component analysis,no group had been separated.Specimens from different drainages could not be distinguished by mophological comparison and morphometric analysis.To answer whether they had morphologic differentiation,it should be confirmed by molecular biological method and other ways for further study in the future.

Key words: Garra imberba, principal component analysis, morphometics, morphologic diversity