In shallow coastal regions, bacteria are believed to play an important role in the recycling of matter. A study concerning total heterotrophic bacteria and phosphate solubilizing bacterial populations in the water and sediment samples of the Karangadu and Devipattinam, Palk Strait, Southeast coast of India were carried out from July 2008-May 2009. THB and PSB were high in November month. THB was ranged between 5.23-9.75x105 cells ml-1 and 2.36-11.21x105 cells g-1 and PSB was fluctuated between 0.98-5.6x103 cells ml-1 and 1.12-6.84x103 cells g-1 from water and sediment samples respectively. Among all the PSB isolates, twenty proficient PSB strains were selected for phosphatase activity and P solubilization efficiency under in vitro condition.