Abstract: The diversity , component and dist ribution of bacterial hysiological groups and microbial flora in eight soil types of the Tiantai Mountain were studied. The results indicated that the amount of bacteria , fungi and actinomyces is the highest in the soil of Pinus taiwanensis forest , bamboo forest , Rhododendron fortunei forest , and the smallest in Cryptomeria fort une forest soil , which is co-related to the content s of organic matter , net nit rogen , net phosphorus and the litter in soil. The ratios of the bacteria , fungi , actinomyces to the total of microorganisms are as follows : bacteria amount is the most common , actinomyces amount is the next , and fungi is the smallest . Different dist ribution patterns of bacteria physiological groups are recognized. The ratios of aerobic cellulose-decomposing bacteria , aerobic nitrogen-fixing bacteria , ammoniation bacteria , organic phosphorus-decomposing bacteria ,inorganic phosphorus-decomposing bacteria to the net amount of soil bacteria physiological groups are the dominant bacteria groups. The ratios of anti-nitrify bacteria and anti-vulcanization bacteria to the soil bacteria physiological groups net amount are the next in eight soil types of the Tiantai Mountain. The Simpson index and Shannon-Wiener index of the bacteria physiological groups are smaller in soil of the Heptacodium miconioides forest , bamboo forest , Rhododendron fortunei forest and Chamaecyparis pisifera forest , that of the bacteria physiological groups are relatively larger in the soil of Cryptomeria fortune forest , tea plantatio forest ,Pseudolarix amabilis forest , and Pinus taiwanensis forest .