Labile and recalcitrant organic carbon fractions of red paddy soils under different fertilization practices for 22a were analyzed by two acid hydrolysis methods with H2SO4 and HCl, respectively. The fertilization treatments include: (1) CK，(2) N，(3) P，(4) K，(5) NP，(6) NK，(7) NPK，(8) 2NPK，(9) NPK+OM. Results showed that the two acid hydrolyzed methods agreed with each other very well. Compared to the CK without anything amendments, fertilization generally increased total organic carbon contents of paddy soil. Except the treatment K with only potassium fertilizer, labile organic carbon contents increased in other fertilization treatments. However, only N and NPK+OM treatments promoted Labile index (LIC) of organic carbon significantly (P<0.05), and especially the LIC in NPK+OM increased to a great extent. Also compared to the CK, fertilization, but not N treatment, consistently increased the recalcitrant carbon contents with the effects of NPK+OM being more significant (P<0.05). In terms of Recalcitrance index (RIC), significantly higher RIC was found in K treatment but the lower values found in N and NPK+OM treatments (P<0.05), indicating the contribution of N fertilizer and organic manure to total organic contents being mainly attributed to the labile organic carbon. Therefore, our results imply that we can manipulate red paddy soil organic carbon contents and stability by optimizing fertilization practices, possibly through selecting appropriate organic amendments, reducing N fertilization and enhancing K fertilization.