Abstract:[Objective] To alleviate the global climate change is one of the most important environmental challenges facing mankind. Autotrophic microorganisms, especially those in forest ecosystems, have been reported to have a strong ability to adapt to environmental changes and a high potential to sequestrate carbon. However, how their carbon-sequestrating effects vary with type of forests vegetation remains unclear. To explore this complex relationship, investigations were made of populations and community structures of soil carbon-sequestrating bacteria in the soils of four typical subtropical forests.[Method] Soil samples were collected from the surface (0-20 cm) and subsurface (20-40 cm) soil layers in the four types of forests, that is Moso banboo, Broad-leaved trees, Chinese fir and Masson pine for analysis of cbbL as indicator gene with the aid of quantitative PCR and MiSeq high-throughput sequencing technology.[Result] Abundance of the bacteria with 16S rRNA genes and those with cbbL genes varied in the range of 5.40×1010-2.81×1011 copies·g-1 dry soil and of 4.55×108to 3.53×109copies·g-1dry soil, respectively, in the four types of forest soils, and was the highest in the soil under bamboo groves (P<0.05); among soil physico-chemical properties, soil available P and soil pH was significantly related to the abundance of cbbL genes in the two soil layers under the broad-leaved forest (P<0.05). The soil under the Chinese fir forest was significantly lower than the others, and the subsurface soil was higher than the surface soil in diversity of carbon-sequestrating bacteria (P<0.05). Double factor variance analysis shows that the diversity of soil carbon-sequestrating bacteria varied significantly or ultra-significantly with forest type and soil layer. All the soils had similar dominant species of cbbL-carrying bacteria, which, however, differed in relative abundance beteween the four types of vegetations. The soil of the Moso bamboo groves and the Chinese fir forest was signiticantly higher than that of the Broad-leaved forest and Masson pine forest in proportion of Methylibium and Nocardia. Redundancy analysis (RDA) shows that soil pH, organic carbon, available P and total N were the main factors affecting the formation of community structure of the soil carbon-sequestrating bacteria in the soils.[Conclusion] To sum up, all the findings in this study indicate that population and community structure diversity of the soil carbonsequestrating microbes varied with type of the vegetation. Comparison of the four forest soils in soil physico-chemical property, and genetic abundance, diversity and community structure of the carbon-sequestrating bacteria shows Moso bamboo groves are the best type of vegetation benefitting soil fertility and carbon-sequestrating bacteria. Contribution of the bacteria to accumulation of organic matter was higher in the soil under bamboo groves than under broad-leaved forests, but as to how much, further investigations should be done.