This study carried out during April ???????????????? to March ????????????????, for identification and determination of abundance of phytoplankton in Park-e-Dolat coastal waters of Bandar Abbas, Persian Gulf. During one year of study and monthly sampling, ???????? genera consist of ????????
genera of diatoms, ???? genera of dinofelagellata, ???? genus of blue-green algae Oscillatoria and one genus of green algae Zygnema were identified. The maximum and minimum diversity of phytoplankton were in January (???????? genera) and in March (???? genera), respectively. The maximum and minimum abundance of phytoplankton were in June (????????????????????????????????????cell/m???? and ???????????????????????? ) and in March (????????????????????????cell/m???? and ???????????????????? ), respectively. Oscilatoria sp. was the most abundant phytoplankton during one year in coastal waters of Bandar Abbas (????????????????????????????????????????????cell/m????). Environmental parameters including sea surface temperature, salinity, dissolved oxygen and pH were studied monthly during the study period and were ????????????????????????????????????????°C, ????????????????????????????????????????ppt, ????????????????????????????????????mg/l and ????????????????????????????????????, respectively. There was not a significant relationship between environmental parameters and diversity, abundance and frequency of phytoplankton during one year (Pearson coefficient, P>????????????????), but only, there was a negative significant relationship between salinity and diversity of phytoplankton (r????= -????????????????, P<????????????????).