Variation in body shape can reflect ecological and behavioural differences. Since water is condensed, body shape particularly affects behavioural performance in fishes and other aquatic organisms. Hence, this study aimed to compare morphological characteristics of Chub populations ( Squalius . ) in Iranian basins using geometric morphometric methods. For this purpose, 542 specimens of Squaliusturcicus from Urmia lake basin (Balanish and Zarrinehrud Rivers) and Caspian Sea basin (Babolrud, Palangabrud, Talvar, Tajan, Tonekabon, Chalackrud, Divandareh, Zarrinrud, Zalkie, Sefidrud,Shafarud, GhezelOzan, Kasma, Nekarud, Noor, Haraz rivers), 23 specimens os Squalius berak from Tigris basin (from Ab-barik River) and 146 specimens of Squalius namak (from Jajrud, Khaznagh, Golpayegan, Ghinercheh, Gharachi and Qomrud rivers). Nineteen morphometric characteristics including totallength, forklength, standard length, head length, snout length, post orbital length, eye diameter, predorsal length, dorsal fin baselength, postdorsal finlength, preanal lentgh, anal fin baselength, postanal finlength, prepectorallength, preventral length. The distance between pectoral and ventral finslength, body depth, cadual fin depth,head depth were measured and 14 meristic characteristics including cadual fin rays, dorasalfin rays, analfin rays, pectoral fin rays and ventral fins rays, number of scales on, above and below lateral line, predorsal midline scalesand cricumpeduncel scales were counted under a stereomicroscope. Pictures were taken from the left side of the specimens and digitized using 13 landmarks in tpsDig2 software. After Procrust analysis the data were analyzed with multivariate statical methods including Principal component analysis, Canonical variationanalysisand cluster analysis. Comparing traditional morphometric showed that significant differencesin all characteristics in studied populations of S. turcicus from southwestern Caspian Sea basin. The results of geometric characters served better than the characters counting for separation of populations (P 0.05).Geometric morphometric comparison showed significant difference among the populations (P 0.0001). The major differences were depth and shape of the head, repositioning of mouth, body depth and length of caudal and anal fins location. Keywords : Geometric morphometric,Morphometric characteristics, Landmark, Procrust analysis