Study was on the existing states and differential characteristics of three forms of the iron oxides different land use systems of brown soil. The results show: (1) the number of free iron oxides or active iron oxides or crystal iron oxides are different in the surface horizons of different land use systems. (2)the variation of free degree and activation degree show that till can promote the product of free iron oxides and hold back to form crystal iron oxides. (3) In the range of 0~60cm of the pedons, three kinds of iron oxides gathered downwards, but their mobility are different. The conversion and distribution of iron oxides related with organism and composition of particles is a compound process.