Nitrogen release experiments and field experiments were conducted to study release characteristics of the controlled release fertilizer(CRF) coated with hydrophobic material(organic macromolecule polymer) and its effect on rice yield as compared to common urea fertilizer(CUF).The results show that nutrient release of the CRF in water met the requirements for controlled-release.Compared with the CUF,the CRF significantly increased the contents of alkalytic N(ALR-N) and NH₄⁺-N in the paddy soil,facilitating N uptake by the roots of rice.There was no difference in total biomass of the rice plants between the different nitrogen treatments,but the results of two years' field experiments show that the grain yield of the rice in the CRF treatments was 10%~40% greater than that in the CUF treatments.Especially,the CRF,applied at a rate only 1/3 of the rate of the CUF,also increased the grain yield of rice by 15.1% in 2003.Under the local paddy field conditions,the results proved that the nitrogen use efficiency of CRF was up to 51.2% in 2002.The CRF showed its advantages of controlling release of N nutrient,promoting N uptake by the rice,increasing grain yield and nitrogen use efficiency,and reducing nitrogen application rate.