Litters are the important component of forest ecosystem and play a key role in plant growth and ecosystem nutrient cycle. Soil microbial communities, as one of the driving factors of forest litter decomposition, can significantly influenced by composition of litters. To understand the responses of carbon metabolism diversity of soil microbial communities to the leaf litter composition plays a key role in the sustainable management of plantations. We designed a simulation experiment with flowerpots at the Ecological Benefit Monitoring Station of the Yangtze River Protection Forest, which is located in Hengyang County of southern Hunan Province, to determine the impacts of litter composition on carbon metabolism diversity of soil microbial communities. The litters of masson pine (Pinus massoniana), slash pine (Pinus elliottii), white oak (Quercus fabri) and blue Japanese oak (Cyclobalanopsis glauca), which are all the typical species of the southern China, were chosen as study species. With the BIOLOG method, the carbon metabolism diversity of soil microbial communities were studied during the decomposition of different leaf litters, including two single coniferous leaf litter treatments (masson pine and slash pine) and four coniferous and broadleaf mixed litter treatments (masson pine+ white oak, masson pine+ blue Japanese oak, slash pine+ white oak and slash pine+ blue Japanese oak). The results showed that: (1) the decomposition of coniferous and broadleaf mixed litter increased the carbon metabolic intensity, richness and diversity of soil microbial communities in comparison with the decomposition of single coniferous leaf litter. Soil microbial communities under the coniferous and broadleaf mixed litters had significantly different carbon metabolic patterns in comparison with those of the single coniferous leaf litter treatment. In comparison with those of single coniferous leaf litter treatment, soil microbial communities under the coniferous and broadleaf mixed litters had higher utilization ability for the following carbohydrates: Tween 80, Phenylethylamine, 4-hydroxy benzoic acid, D-mannitol, N-acetyl-D-glucosamine, D-galacturonic acid, γ-hydroxy butyric acid, D-glucosaminic acid and D, L-α-Glycerol phosphate. (2) At the early stage of litter decomposition carbon metabolic intensity, richness and diversity of soil microbial communities showed significantly negative correlation with the initial carbon-nitrogen ratio of litters. However, at the latter stage of litter decomposition carbon metabolic intensity of soil microbial communities correlated with the initial lignin-nitrogen ratio of litters negatively (P<0.05) and the carbon metabolic diversity correlated with the initial phosphorus concentration of litters positively (P<0.05). (3) The species composition changes of litter significantly altered the intensity and diversity of carbon metabolism of soil microbial communities due to different carbon-nitrogen ratio, lignin-nitrogen ratio and phosphorus concentration. The coniferous and broadleaf mixed litter strengthened the carbon metabolic function of soil microbial communities in comparison with single coniferous leaf litter in hilly red soil region of southern China.