Rice straw and pig manure are the important exogenous organic substances for the improvement of Soil Organic carbon (SOC) storage capacity in upland red soil.Different amounts of rice straw and pig manure with equal carbon were mixed with tested soils and incubated indoor for 235 days,after which the SOC was divided into Particulate Organic carbon (POM),Sand & stable Aggregate carbon (S+A),Dissolved Organic Carbon (DOC),readily oxidizable organic carbon (s+c-rSOC) and inert organic carbon (rSOC) components according to the physiochemical fractionation method,and then various SOC fractions were reclassified as the Decomposable Plant Material (DPM),Resistant Plant Material (RPM),Humified organic matter (HUM),microbial biomass (BIO) and Inert Organic Matter (IOM) based on the RothC model.The results show that the soil Total Carbon (TC) and various organic carbons were significantly increased by the equal-carbon additions of rice straw and pig manure,but the effect of rice straw addition on the TC,DPM,RPM and IOM was significant higher than that of pig manure,while its effect on the BIO and HUM was significantly lower than that of pig manure.As the incubation continued,the proportion of IOM in TC gradually increased,while the proportions of DPM,RPM,BIO and HUM in TC gradually decreased.The increase of f-Fe₂O₃ could significantly increase the DOC in upland red soil (P<0.05).The increase of a-Fe₂O₃ could significantly promote the decrease of DOC and the increase of IOM component (P<0.05),while the increase of a-Al₂O₃ could significantly increase the POM,BIO and HUM (P<0.05),and significantly reduce the DOC (P<0.01).It can be concluded that in short term,the addition of rice straw with equal carbon content is more beneficial to the storage of TC,DPM,RPM and IOM (rSOC),while the addition of pig manure is more beneficial to the storage of BIO and HUM.However,with the prolonging of the incubation time,the active carbon pools such as DOC,IOM (rSOC) and chemically protected carbon pools in upland red soil would significantly increase by the equal-carbon additions of rice straw and pig manure.