Tiab and Kolahy estuaries are regarded as part of the Ramsar sites, that are located in the delta of Rud Shirin, Rud Shour and Minab River 37o 05' N 56o 50' E. The total area of the region is about 20000 ha. In this study, 96 species from 27 families of the birds of Iran were recognized at these wetlands.Fifty seven species were waterbirds. Species of White and Dalmation Pelicans,Great Cormorant, Greazer Flamingo and some Gulls and Terns were counted monthly in this survey. All species were migrant birds. Density of birds population in Kolahy was 2/99 and in Tiab 3,00 per hectare. There was no significant statistical difference between populations and species diversity of any known species in both estuaries. The bird's population in both wetlands were maximum in winter and minimum in summer, from which 60% were Fish-eating, 35% omnivores and the remaining were Plankton-eater.Dalmation Pelican Pelecanus crispus, one of the threatened species observed in winter in both estuaries. Diversity of Sternidae with 9 species was more than the other bird family and Phoenicopterus ruber and Phalacrocorax carbo with one species werethe families with lowest bird species number.