The contents of amporphous Fe and Al oxides and complexed Fe/Al oxides inereased to varying degrees in the soil and its organomineral complex under application of organic manures for 9 years, and there existed an antagonism between tomplexed Fe oxide and complexed Al oxide (r=0.7998 n=7). The increase in the contents of soil organic matter was principally due to the increase in the contents of organic matter in light fraction, and degree of organo-mineral complexing in soil was decreased. The rate of loosely combined arid tightly combined humus in heavy fraction was comparatively increased. The sequence of organic matter in complexes was 0.25-0.01lmm> <0.002mm>1-0.25mm>0.01-0.002mm, and the degree of organo-mineral complexing and the rate of loosely combined and tightiy combined humus declined with the particle size and their average degrees of complexing were significantly lower than those in the soil. The content of Fe₂O₃ and the rate of Fe/C in soil loosely combined humus were higher, but the content of Al₂O₃ and the rate of Al/C were lower, and the contents of Fe₂O₃, and Al₂O₃, in humic acid were lower than those in fulvic acid. The sequence of contents of Fe₂O₃ and Al₂O₃ in loosely combined humus in complexes was consistent with that of the content of organic carbon.