Tropical coastal forests are an important carbon pool and are easily disturbed by human activities, including deforestation and climate change. Therefore, it is urgent to explore the organic carbon storage of forest soil, which provides a theoretical basis for the protection and restoration of tropical coastal forests. We estimated the soil organic carbon (SOC) storage and its vertical distribution under typical forest types, including secondary natural forest of S. odoratum, Coconut plantation, Acacia plantation, Casuarina plantation in the coastal tropical zone. The results showed the vertical variation of soil organic carbon and total nitrogen in the soil profile was consistent with the vertical variation of soil organic carbon and total nitrogen, the content of SOC and total nitrogen (TN) decreased with increasing soil depth on all of the four soil profiles, and the content of SOC and TN showed significant differences among layers. The content of SOC and TN in Coconut plantation was the highest among the four forest types ( 7.06 g/kg and 0.61 g/kg, respectively), followed by the natural secondary forest of S. odoratum (6.07 g/kg and 0.44 g/kg). The mean C/N was in the descending order of Acacia plantation (19.7), Casuarina plantation (19.3), secondary natural forest of S. odoratum (14.8), and Coconut plantation (11.5). The content of SOC and TN in the four forest soils ranged from 1.35 to 7.06 g/kg and from 0.08 to 0.61 g/kg. The descending order of SOC storage of 0 -100 cm soil layer was Coconut plantation ( 48.09 t/hm~2), secondary natural forest of S. odoratum (41.98 t/hm~2), Acacia plantation (14.28 t/hm~2), and Casuarina plantation (12.06 t/hm~2). Correlation analysis showed significantly negative correlations between SOC and soil bulk density, and positive correlation between TN, but no significant correlations between soil water content. Coconut plantation and secondary natural forest of S. odoratum were the ecosystem equilibrium, and the carbon sequestration benefits than Casuarina plantation and Acacia plantation significantly. Our research has important significance for the management and maintenance of the tropical coastal forest.