Abstract: The biomass and net productivity of Sonneratia apetala and S. caseolaris man-made forest in Shenzhen Futian Nature Reserve were measured. The power regression equations were obtained using the biomass data of leaves, stems, twigs, flowers, cones, and barks, respectively. The analyses of biomass allocation showed that the litter fall productions of S. apetala, S. caseolaris, and Kandelia candel were leaves >flowers and cones >twigs. Considering the community ages and densities of plantation, the biomasses of Six-years old are higher than that of other species.