In five types forest, Quercus mongolicaand–Populus davidiana, Acer ukurunduense–Quercus mongolicaand, Larix kaempferi, Populus davidiana and Betula platyphylla–Populus davidiana forests, in headwater catchment of eastern mountainous of Liaoning province, we studied the effects of species composition, diversity and richness factors on the contents of soil organic carbon, microbial biomass carbon and soil soluble organic carbon. Our results showed that, the contents of soil organic carbon, dissolved organic carbon were the highest in Larix kaempferi forest and lowest in Populus davidiana. The contents of microbial biomass carbon were the lowest in Larix kaempferi forest. The contents of soil organic carbon, dissolved organic carbon and microbial biomass carbon were significantly higher in 0–10 cm soil layers than >10–30 cm soil layers. The content of soil microbial biomass carbon was positively correlated with spices diversity and richness, and the impacts of diversity and richness for trees were higher than shrubs and herbs. The contents of soil organic carbon, dissolved organic carbon of shrubs were negatively correlated with biomass, diversity and richness for trees, shrubs and herbs, and the effects were weaker over soil depth.