Abstract:‘3414’ field trial was adopted to study the appropriate rate of fertilizer application and efficiency of fertilizer usage in relay cropping rice with wheat,a new cropping system in Danjiangkou region.Results showed that the yield of relay cropping rice was mainly determined by the effective panicle number per hectare and total grains per panicle.Appropriate application of N,P and K fertilizer increased yield significantly and farmer’s economic income.The highest grain yield reached up to 6 889 kg/hm2 when the rate of fertilization was N 168.0 kg/hm2,P2O5 75.0 kg/hm2 and K2O 90.0 kg/hm2.Among the effects of N,P and K fertilization,the increase of yield and economic income decreased in the order of N>K>P.The highest increment of yield was 3 316 kg/hm2 with an increment rate of 92.8% and the apparent nutrient efficiency of 52.9% under N application.The highest increment of yield,the increment rate and the apparent nutrient efficiency was 546 kg/hm2,8.6% and 13.0% under P application,and 699 kg/hm2,11.3% and 69.8% under K application.The modeling of fertilization effect showed that the appropriate rate of applying N,P2O5 and K2O was 188.0,30.0 and 85.0 kg/hm2 and the designable yield was 6 997 kg/hm2 in relay cropping rice with wheat in this region.