This study presents the natural regeneration status and tree species diversity of the Sitakund Botanical Garden and Eco-park, Chittagong, Bangladesh. The study area was classified as disturbed and less disturbed zones based on the current anthropogenic disturbances. Stratified and systematic random sampling was used to select the sample plots, 30 in less disturbed zone and 20 in disturbed zone. A total number of 109 plant species from 43 families were recorded in the study, of which 93 were naturally originated species and rest were planted. Among the naturally originated species 66 were tree species, 9 were shrub species and 18 were climbers. The average densities (N/ha) of height range (0 - 0.5) m, (0.5 - 2) m, (> 2 m < 6 cm dbh) and trees (> 6 cm dbh) were 72333, 11291, 2770 and 790 in the less disturbed zone and 122500, 12687, 1640 and 150 in the disturbed zone respectively. The average basal areas (m2 / ha) in the disturbed and less disturbed zone were 3.29 and 6.80 respectively. Holarrhena antidysenterica, Stereospermum chelonioides, Dehasia kuruzi, Garuga pinnata, Albizzia procera, Kurulla were dominant tree species in the disturbed zone and Holarrhena antidysenterica, Stereospermum chelonioides, Dehasia kuruzi, Garuga pinnata, Syzygium fruticosum, Ficus hispida were dominant tree species in the less disturbed zone.32 trees and 9 climbers were common in both zones. Herb coverage in the disturbed and less disturbed zone was 67% and 40% respectively. Most of the shrub species were common in both zones. Species richness, density (N / ha) for regeneration from (0 - 0.5) m range and trees (> 6 cm dbh) and disturbance index showed significant differences between zones. Species richness and basal area (m2/ha) showed a negative relationship with disturbance index. Number of total individuals decreased as the diameter and height of trees increased. It is evident from the results that plant species richness and tree species diversity were influenced by the level of anthropogenic disturbances. Therefore, native forest eco-system could be restored if the anthropogenic disturbances can be minimized.