Chinese milkvetch(CM) has been cultivated as green manure source for environment friendly farming in southern area. This experiment was conducted to produce good quality rice through studying the changes of yield, quality and leaf colors as affected by the amount of CM biomass retuned to paddy field. We growed rice, transplanted in June 10 with cultivar dongjinilho, in four different plots retuned green manure with 0, 1.5, 3.0, and 4.5 ㎏ m-2 CM biomass in May 30. Nitrogen amounts were 5.5g by 1.5㎏CM biomass, 11.1g by 3.0㎏, and 16.6g by 4.5㎏ in late May. There were no different SPAD values among treatments in 10 days after transplanting. However, the more the CM biomass from 20 days after transplanting, the higher the SPAD values were. the plot of CM biomass to 3.0 ㎏ m-2 had same heading date but the plot of 4.5 ㎏ m-2 was one day late heading date as compared with the others. There were no different plant height, number of panicle, panicle length, number of leaf and ripening ratio among the CM biomass amounts. The higher the CM biomass amount, the more likely the plant was lodge. the plot retuned CM fresh biomass 1.5 ㎏ m-2 showed the higher rice yield than the plot retuned 3.0 and 4.5 ㎏ m-2 in 2006, but all plots had similar rice yields in 2007. There was no different whiteness of rice among all treatments . The more the CM biomass amount retuned to plot, the higher the protein content of rice.