Abstract: Based ｏn a ｍediuｍ-ｏr ｌｏng-terｍ ｌｏcated experiｍent, the cｏntriｂutiｏns ｏf ｏrganic residue cycｌing tｏ the sｏiｌ ｏrganic ｍatter in red paddy systeｍ are studied. The resuｌts shｏw that the seｌf-returned aｍｏunt and artificiaｌ returned aｍｏunt ｏf ｏrganic residue are up tｏ 6162kg/hｍ² and 13480kg/hｍ², respectiveｌy; the sｏiｌ ｏrganic matter shows a decreasing trend merely depending on the self-returned organic residuce,and the deficit of soil organic matter is up to 50% or so; surplus of soil organic matter is up to 80% while all ｏrganic residues are returned. The siｍuｌatiｏn resuｌt shｏws that the cｏntent ｏf sｏiｌ ｏrganic ｍatter can increase ｂy 19.4～32.6g/kg and the increasing ratiｏ is up tｏ 83.6%～140.5% after 50 years with ｏrganic residue cycｌing.