Diversity and distribution pattern of tree species of Bamu Reserved Forest of Cox’s Bazar were studied by count plot method for analysing stand composition. A total of 85 tree species were recorded from the forest of which 77 species belonging to 30 families were identified. Leguminosae and Moraceae ranked top with seven species followed by Verbenaceae and Euphorbiaceae each with six species. The Importance Value Index (IVI) of each species was calculated to characterize the composition of vegetation. Bursera serrata showed the highest (18.91) IVI followed by Artocarpus chania (14.82), Pterospernium acerifolium (14.04), Hopea odorata (13.73), Glochidion multiloculare (13.19) and Vitex peduncularis (10.51). Distribution of the number of individuals of each species in nine diameter classes (<10cm – > 80cm with 10cm intervals) were calculated with respect to total individuals. It showed that maximum percentage of individuals (35.08%) belonged to <10cm diameter class, while largest diameter class (>80cm) represented the lowest percentage (1.82%). Bursera serra tahad the highest (8.04%) percentage distribution followed by Glochidion multiloculare (7.67%), Dipterocarpus turbinatus (5.85%), Hopea odorata (5.36%), Pterospernium acerifolium (4.87%), Bauhinia acuminata (4.03%) and Lagerstroemia speciosa (3.05%). The rest of the species had values < 2.8%.