Background: The present work was conducted on some soil samples collected from Shamnagar upazila of Satkhira district of south-west part of world largest mangrove forest Sundarban Rezion, Bangladesh which were affected by natural disaster cyclone Aila. Materials and Methods: The soil samples were analyzed to determine terrestrial γ-ray activity using HPGe γ-ray spectrometry. The measurements conducted in the current study showed that primordial radionuclides namely the ²³⁸U and ²³²Th and ⁴⁰K are contained in all the soil samples. Results and Discussion: The obtained results of the average activity concentrations of ²³⁸U, ²³²Th and ⁴⁰K were found to be within the range of the world average of 17-60, 11-64, 140-850 Bq.kg^-1 reported by UNSCEAR. The radiation dose is below the permissible limit of 1mSvy^-1 recommended by IAEA (2007). No peak of ¹³⁷Cs from the decay activity was found in the spectrum in the present work. Conclusion: The present work will be useful in providing environmental monitoring data base of those particular areas.