[Objective] Mangroves are part of a wetland ecosystem found along tropical and sub-tropical coastlines. The soil active organic carbon composition, soil enzyme activity, and the interaction between them, under different plant community conditions was analyzed in order to predict the ecological structure and functional development trend of the mangrove area in Dongzhai Port, and provide a scientific basis for ecological restoration and protection of the mangrove wetland in Dongzhai Port. [Methods] Soil enzyme activity, active organic carbon content in the soil, and physicochemical properties of nine mangrove communities 〔Rhizophora stylosa (Type 1), Avicennia marina (Type 2), Ceriops tagal (Type 3), Bruguiera sexangula + C. tagal (Type 4), Aegiceras corniculatum + B. sexangula + Kandelia obovata (Type 5), B. sexangula + Lumnitzera racemose + A. corniculatum (Type 6), K. obovate + B. sexangula + L. racemose (Type 7), B. sexangula + Sonneratia apetala + A. corniculatum + K. obovata (Type 8), B. sexangula + S. apetala (Type 9)〕 were analyzed by field sampling. [Results] Soil organic carbon ranged from 6.57 g/kg to 74.87 g/kg in Dongzhai Port, with Type 7 and Type 1 communities having the highest and lowest soil organic carbon contents, respectively. Enzyme activity of wetland soil in each mangrove community followed the order of urease ＞ phosphatase ＞ catalase ＞ sucrase. Type 8 community had the highest urease activity, significantly higher than Type 1 to Type 6 communities. Moreover, Type 8 community also reported the highest phosphatase activity, which was significantly higher than phosphatase activity for Type 1 to Type 3 communities. On the other hand, catalase activity was highest in Type 5 community, and significantly higher than in the other communities, except Type 6 and Type 7. Type 9 community recorded the highest sucrase activity, which was significantly higher than Type 2, Type 5, and Type 8 communities. Furthermore, it was found that urease, phosphatase, and catalase activities had significant positive correlations with soil organic carbon content. Urease and phosphatase activities were significantly negatively correlated with soil pH value, and significantly positively correlated with total nitrogen (TN) and total phosphorus (TP). Catalase and sucrase activities also had significant positive correlations with TN and TP. The redundancy analysis results indicated that light fraction carbon, total organic carbon, particulate organic carbon, and microbial biomass carbon (MBC) were the main factors affecting soil enzyme activity of mangrove communities in Dongzhai Port. [Conclusion] There was a strong positive correlation between soil enzyme activity and the carbon content of active organic matter. Therefore, soil enzyme activity can be used to characterize the soil carbon pool activity in the mangrove area of Dongzhai Port.