A long-term stationary field experiment was carried out to study the effect of application of organic manure,chemical fertilizers or their mixture on soil carbon storage and carbon fixation by plants.The experiment was designed to have 7 treatments;organic manure (OM),half organic manure plus half fertilizer N(1 /20M),fertilizer NPK(NPK),fertilizer NP(NP),fertilizer NK(NK),fertilizer PK (PK) and control(CK).The treatments,supplied with balanced nutrients of N,Y and K,showed a marked increase in the storage of soil organic carbon,while those deficient in nutrient supply a significant decrease.Only in Treatments OM and 1/20M,where additional organic carbon was supplied,a net uxrease in organic carbon in the soil was observed.The relationship between the storage of organic carbon(Y) and the input of organic carbon(X) can be well described by the following linear equation:Y=1.3231 X-1942.7(r=0.9840,n=7).Treatments NPK,NP and 1/20M were the highest in both crop carbon fixation and organic carbon contents in crop straws and stubbles that can be returned to the soil.So,if the fixed carbon in the straws and stubbles return to the soil,Treatments NPK.NP and I/20M would have the biggest storage of organic carbon in the experiment.However,the combined application of chemical fertilizer and organic manure is the optimal for agricultural field based on economic consideration.