Selecting suitable sites for the establishment of cage based aquaculture has a very important role in aquaculture development and investment success. In Iran, there is a growing tendency for seawater aquaculture development due to the limited resources of freshwater. In the present study, the effective biotic and abiotic factors in cage culture that were collected through the hydrological and hydrobiological studies from 1387 to 1389 were analyzed. Iranian waters of the Caspian Sea from shoreline to the depth of 100 meters were investigated with the use of Geographic Information Systems (GIS). Analysis was carried out based on the site selection criteria including the minimum depth of 20 m, short distance from the beach, no interference with other maritime activities, being at least 5 km far from the river mouth and the most suitable environmental parameters. Results indicated that Iranian waters of the Caspian Sea were appropriate for cage culture in which, central region between the cities of Kheshtsar to Kiashahr with an approximate length of 245 km was the first priority and the western and eastern regions were the second and the third priorities for aquaculture development, respectively. In central region, the match compliance criteria for the establishment of floating cages were 80 to 97.5 percent and the suitability of the environmental conditions were increased from the east to the west. Fourteen sites out of the fifteen suitable sites, which had the most appropriate conditions for the establishment of floating cages, were in a region between Chaboksar and the western part of Sepidroud River and the remaining site was in Tonekabon region.