Abstract: In order to reveal the mechanism of natural regeneration in Shimei Bay coastal 灾atica mangachpoi forest from the aspect of soil microorganism, the soil microorganisms in V. mangachpoi forest were investigated and analyzed. Five-point sampling method was used to take the soil samples in both dry and wet seasons form rhizosphere and nonrhizosphere soil, respectively, and the MPN was used to analyze the quantitative distribution of five physiological groups of bacteria in the soil. The results showed that nitrite bacteria was not found in the soil of V. mangachpoi forest, there were obvious differences among the quantities of other four physiological groups of bacteria, the quantities of ammonifying bacteria >> aerobic nitrogens -fixing bacteria >> denitrifying bacteria >> aerobic cellulose decomposing bacteria; the quantities of ammonifying bacteria, denitrifying bacteria and aerobic cellulose decomposing bacteria were less in the rhizosphere soil than in the non-rhizosphere soil, but the quantity of aerobic nitrogens-fixing bacteria was opposite in the rhizosphere and non-rhizosphere soil; the quantity of ammonifying bacteria was slightly higher in the subsoil than in the upper soil, but quantities of the aerobic nitrogen-fixing bacteria, denitrifying bacteria and cellulose decomposing bacteria were more concentrated in the upper soil.