A field experiment was conducted at Jiangtang Agricultural Experiment Station，Jinhua City, Zhejiang Province, China to explore effects of incorporation of Chinese milk vetch coupled with application of chemical fertilizer on nutrient uptake, nutrient use efficiency, and yield of single-cropping late rice and hence to determine optimal application rate of chemical fertilizer in addition to incorporation of Chinese milk vetch at the rate of 45 t hm^-2 fresh grass (GM₄₅). The experiment consisted of 7 treatments: CK (no fertilizers and no Chinese milk vetch), CF (conventional chemical fertilizer rate), GM₄₅, GM₄₅+20�, GM₄₅ 40�, GM₄₅ 60� and GM₄₅ 80�. Results of the 2 year (2011-2012) field experiment show that among all the GM₄₅ treatments, Treatment GM₄₅ 80� was the highest in total N, P, and K uptake by rice, but Treatment GM₄₅ 40�, the highest in N, P, and K uptake by grain, and the internal nutrient use efficiency decreased with increasing chemical fertilizer application rate. However, treatment GM₄₅ 40� was the highest in both NPK agronomic use efficiency and grain yield. From the angle of improving fertilizer use efficiency and reducing environmental risk, in addition to incorporation of 45 t hm^-2 of fresh Chinese milk vetch produced in other fields, N 80.6 kg hm^-2, P₂O₅21.5kg hm^-2 and K₂O 43.3 kg hm^-2 are recommended. Compared with treatment CK, treatment CF and treatments (GM₄₅, GM₄₅ 20�, GM₄₅ 40�, GM₄₅ 60� and GM₄₅ 80�) increased grain yield by 13.7% and 8.5%～17.4%, respectively. In the cropping system of Chinese milk vetch – single-cropping late rice, incorporation of 45 t hm^-2 fresh Chinese milk vetch will not result in the seedling.