Studying fish in aquatic ecosystems is important in many ways, including behavioral, ecological, biodiversity management and conservation, exploitation of their reserves and rearing. Therefore, this study aimed to compare morphological characteristics of Alburnus chalcoides populations in Caspian Sea using geometric morphometric method. For this purpose 424 specimens were sampled from the Caspian basin. Three traditional trait including total length, fork length and standard length and weight and 17 meristic traits including number of unbranched and branched dorsal fin rays, unbranched and branched abdominal fin rays, unbranched and branched pectoral fin rays, rudimentary and principal caudal fin rays, number of gill rakers, number of lateral line scales, scales above and below the lateral line, predorsal and circumpeduncle scales were counted. Photos were taken from the left side, then the 14 selected landmarks were digitized using tpsDig2 softwar. Data were analyzed by CVA and PCA multivariate analysis. In the Caspian Basin, the distinction between the 15 populations under study showed that the populations in the Caspian Basin were significantly different in all studied traits (meristics and morphometrics) except for the number of unbranched dorsal, ventral, thoracic and anal fins (p 0.05). Canonical variance analysis (CVA) based on p value of permutation test showed that there was a significant difference (Wilks lambda = 0.001214, p 0.00000) between body shape of the studied populations. Examination of changes in body shape patterns of the studied populations showed that major changes and variations in body shape were related to head size, dorsal fin base length, and tail length. Keywords: Geometrical Morphometry, Morphological Properties, Landmarks, Procrustes Analysis