Changes in soil carbon pools under Chinese fir (Cunninghamia lanceolata) and bamboo (Phyllostachys pubescens) plantations substituted for a native forest (Quercus acutissima, Cyclobalanopsis glauca, Gas-tanopsis sclerophylla, Platycarya strobilacea, Lithocarpus glaber) were studied on the hills with acid parent rock and soils classified as red soils (Ferrisols) in Huzhou, Zhejiang Province of east China. It was found that total soil organic carbon (TSOC), easily oxidisable carbon (EOC) and water-soluble organic carbon (WSOC) under bamboo plantation were increased, but microbial biomass carbon (MBC) was decreased. On the contrary, Chinese fir induced declines of all fractions of C including TSOC, EOC, WSOC and MBC. The percentages of the active fractions of soil C (EOC and WSOC) were increased in the plantations as compared to the native broad-leaved forest, but proportions of soil organic C as MBC were decreased. It could be concluded that bamboo plantation had a great ability of not only fixing C but a Changes in soil carbon pools under Chinese fir (Cunninghamia lanceolata) and bamboo (Phyllostachys pubescens) plantations substituted for a native forest (Quercus acutissima, Cyclobalanopsis glauca, Gas-tanopsis sclerophylla, Platycarya strobilacea, Lithocarpus glaber) were studied on the hills with acid parent rock was so classified as red soils (Ferrisols) in Huzhou, Zhejiang Province of east China. It was found that total soil organic carbon (TSOC), easily oxidizable carbon (EOC) and water-soluble organic carbon increased, but microbial biomass carbon (MBC) was decreased. On the contrary, Chinese fir induced declines of all fractions of C including TSOC, EOC, WSOC and MBC. The percentages of the active fractions of soil C (EOC and WSOC) were increased in the plantations as compared to the native broad-leaved forest, but proportions of soil organic C as MBC were decreased. It could be concluded that bamboo plantation had a great ability of not o nly fixing C but a