Mineralization of soil organic carbon is an important biochemical process closely related to release and supply of nutrients,formation of greenhouse gases,and maintenance of soil quality.In incubation experiments and chemical analysis of soil samples of Udic Isohumisols,Udic Cambosols,Hapli-Stagnic Anthrosols No.1 and No.2,Fe-leach-Stagnic Anthrosols,Feaccumul-Stagnic Anthrosols gathered in East China,dynamics of soluble organic carbon content and soil organic carbon mineralization under different moisture treatments were investigated to determine difference in soluble organic carbon content between aerobic and submersion conditions as related to change in mineralization of soil organic carbon.Soluble organic C(SOC) was linearly and significantly related to wate-rsoil ratios ranging from 1:1 to 10:1,with different correlation coefficients(R²) in the soils(Udic Isohumisols 0.908^**,Udic Cambosols 0.973^**,Hapli-Stagnic Anthrosols No.20.933^**,Fe-leach-Stagnic An-hrosols 0.901^**,Fe-accumul-Stagnic Anthrosols 0.865^**).Cumulative SOC increased with the extracting time and SOC from a single event decreased with the frequency of the extraction.During the 8 weeks incubation,soluble organic C in the submergence treatments was 46% ~117% (p<0 05) for Hapl-i Stagnic Anthrosols No.1,112% ~285% (p<0 001) for Hapli-Stagnic Anthrosols No.2,and 21% ~73% (p<0 05) for Fe-accumul-Stagnic Anthrosols,higher than those in the aerobic treatments.In the first 3 weeks(for Hapli-Stagnic Anthrosols No.1) or 4 weeks(for Hapl-i Stagnic Anthrosols No.2) of incuba- tion,the daily mineralization of soil organic C was significantly different between moisture treatments(p<0 01),and tended to be similar thereafter;and the cumulative mineralization of soil organic C was significantly higher in the submergence treatment than in the aerobic treatment for the whole incubation period(p<0.01).Dynamics of the mineralization of soil organic C and trend of the change in content of soluble organic C tended to be similar,especially for Hapli-Stagnic Anthrosols No.2,which showed significant correlation coefficients(r) between soil organic C mineralization and soluble organic C content(0.942 in the aerobic treatment and 0.975 in the submergence treatment).Results also showed that difference in soil organic C mineralization(including daily and cumulative mineralization) between Hapli-Stagnic Anthrosols No.1 and No.2 was mainly related to their significant difference in content of soluble organic C,not the total soil organic C content.Significant increase in soluble organic C content as a result of submergence might be the main cause for a higher mineralization of soil organic C under the submersion condition than under the aerobic condition.