The coastal zone of the Oman Sea (Sistan and Baluchestan province) with 300 Km length is a rich habitat of different species of seaweeds. In order to determine the species identification and distribution of seaweeds, 11 stations were selected and samplings were carried out seasonally by scuba-diving method. During this study, 42 species of seaweeds were identified consist of: 3 species of green algae, 17 species of brown algae and 22 species of red algae. The dominant species of brown algae were: Stoechospermum marginatum, Padina australis, Dictyota sp., Sargassum glaucescens and Cystoseira indica. Some important and commercial species of red algae are: Gracilaria corticata, Gelidiella acerosa, Gelidium micropterum, Hypnea musciformis. The green algae were found only in Passabandar and Chabaharegions with the main species of Ulva fasciata. Along with sampling, some environmental factors were measured including: sea and ambient temperature, salinity, pH, growing depth, D.O., substrate structures and slope and transparency. The maximum and minimum growing depth of seaweeds were found in Tang and Gwatr areas, respectively.