Abstract:The temporal changes of soil organic matter (SOM), pH, CEC, content of iron oxides and the distributions of free iron oxides (Fed) and amorphous iron oxides (Feo) in paddy soils cultivated for 7a, 22a, and 80a were studied. All soils were derived from the Quaternary Red Clay and collected from Yujiang, Jiangxi Province. The results showed that SOM content in topsoil (0 – 20 cm) increased with the increase of cultivated year, soil pH increased during rice cultivation of the first 7 years and then changed slightly afterwards. The cation exchange capacity (CEC) increased with the increase of cultivated year, reached the maximum value at the 17th year and then decreased afterwards. The content of free iron oxides in soils decreased with the increase of cultivated year, the ratio of Feo/Fed was higher in paddy soils than in the dry land soil. For 7a and 80a paddy soils, the content of free iron oxides in topsoils were higher than those in subsoils, suggesting that iron transported downwards in soil profiles. The contents of amorphous iron oxides of 7a and 22a paddy soils were higher in topsoils than those in subsoils, but it increased with the increase of sampling depth for 80a soil profiles.