Abstract: This is a paper dealing with the accumulation and biological cycle of the nitrogen and phosphorus elements of the artificial 20-year-old Kandelia candel community, in the Jiulong Jiang river estuary of Fujian Province, China.The main results of measurements are as follows:1. The amounts of nitrogen and phosphorus in the standing crop of this community were 935.47 kg/ha and 112.02kg/ha; in which the amounts of the two elements in the biomass above ground were 582.86 kg/ha for N and 70.47kg/ha for P, and in the biomass underground were (kg/ha) 353.21 for N and 41.55 for P respectively.2. In biological cycle of nitrogen and phosphorus of this stand, the annual values of the vegetation mineral uptake are (kg/ha yr) 213.31 for N and 21.75 for P, and those of retention of are (kg/ha yr) 83.75 for N and 10.91 for P, and the annual amounts released are (kg/ha yr) 129.52 for N and 10.84 for P respectively.3. The speed of nitrogen recycling period (7 yrs.) is faster than that of phosphorus (10 yrs.). The biological decompositional ratio of the mangrove forest in Fujian is larger than that of the tropical rainforest in Yunnan, and it is possible that this is concerned.with the tidal habitat of the mangrove forest.