The long-term fertilization experiments located at the south edges of the Loess Plateau were used to study effects of different fertilizer treatments, i.e., no fertilizer(CK), fallow (FA), NPK fertilizer (NPK), NPK +organic manure(MNPK), and NPK +straw(SNPK), on content, structural characteristics and biodegradation of dissolved organic carbon(DOC) in the soil. The contents of DOC in the surface layers (0~20cm in depth) of soils different in fertilization treatment ranged from 4.65 to 8.94 mg kg^-1, and averaged 6.42 mg kg^-1. The fertilization treatments followed the order of MNPK > SNPK > NPK > FA > CK. The special absorption value at 280 nm (UV280) and the humification index (HIXem) of DOC solution indicated that significant differences existed between soils different in treatment in structural characteristics of DOC, and in terms of proportion of complex aromatic compounds in the soil, the five treatments followed the order of SNPK > MNPK > FA > NPK > CK. After 7 days of biodegradation incubation, the biodegradation rates in the treatments ranged from 19.32% to 48.49%, and averaged 28.58%, and the treatments followed the order of CK > FA > NPK > SNPK > MNPK. The UV280 and HIXem of DOC solution before and after biodegradation indicated that the proportion of dissolved organic matter more complex in structure increased with the duration of incubation.