Abstract: In order to reveal the action mechanism between land use types and soil organic carbon components， five land utilization types， including woodland， shelter forest， aquaculture land， park green land and cultivated land， were selected as the study objects. It was shown that soil organic carbon （SOC） aggregated in the surface layer. Compared to the other land use types， woodland exhibited higher carbon sequestration capacity. The quantity distribution proportion of soil easily oxidized carbon （EOC） exhibited limited variation within the same land use type. The quantity distribution proportion of particulate organic carbon （POC） in 0-10 cm soil layer showed aggregation in park green land， shelter forest， and aquaculture land， and the variation of POC below 10 cm soil layer in these three land use types was small. SOC， EOC and POC contents showed significant correlations among each other at 0.01 level. Compared with SOC and EOC， POC in 0-10 cm soil layer was more sensitive to changes of land use type in park green land and aquaculture land.

Key words: wetland, land use type, soil organic carbon, soil active organic carbon