Abstract: To explore the soil microbial flora and their seasonal changes on different forest types of Pinus massoniana,the cultivable bacteria, Bacillus spp. and fungi in the soil of near-matured forest, middle-aged forest and plantation in Yunyang County of the Three Gorges Reservoir Area were analyzed. The results showed that the species of dominant populations and quantities of soil microbial in forest land soil were different following seasons vary and forest types. The quantities of bacteria in middle-aged forest was significantly higher than that in near-matured forest and plantation, and it changed greatly as seasons change, while the change in near-matured forest and plantation were relatively gentle. The dominant species of bacteria in forest land soil were mainly Bacillus spp.,Pseudomonas spp. and especially Bacillus cereus. The dominant bacterial population was the highest in the winter (near-matured forest> plantation> middle-aged forest), the dominant species in near-matured forest was Bacillus, accounting for 39.74%; that in plantation was Pseudomonas spp., 37.26%; that in middle-aged forest was Bacillus cereus, 24.91%. In the soil of the three types of forest land in different seasons, Bacillus cereus (20% to 49%) and one of the species (unidentification) of Bacillaceae were the dominant species. The dominant fungi species in the soil of the three forest types had the highest proportion in the autumn, and followed the order of plantation> near-matured forest > middle-aged forest; the dominant population and the percentage took in plantation, near-matured forest and middle-aged forest were respectively Sclerotinia sclerotiorum, 33.08%, Sclerotinia sclerotiorum, 31.7%, Penicillium waksmanii, 25.15%.