In order to make sure the control effect of side deep fertilization for resin blending controlled-release fertilizer(RBB)on nitrogen loss in paddyfields,a field experiment with Wuyunjing-23 rice was carried out to study the effectof reduced application of RBB on nitrogen concentration of surface water and rice yield in Taihuarea.Fivetreatments,namely,conventional split fertilization(CN),RBB with conventional applicationrate(RBB1),reduction by 10%(RBB2),reduction by20%(RBB3),and reduction by30%(RBB4),were setup.The results showed that RBBreductions of 10% to 30% did not result in the reduction of rice yields when compared with CN treatment(270 kg/hm 2).The nitrogen in surface water was mainly ammonium nitrogen.And the nitrogen concentration of surface water reached thepeak concentration on the first or secondday,and then decreased after inorganic fertilizerapplication.The control effectof RBB on nitrogen release wasbetter.The peak concentration of nitrogen in surface water in the three fertilizer periods waslow,which was significantly lower than that of CN treatment.As the nitrogen in surface water was mainly ammoniumnitrogen,thereduction of total nitrogen concentration was more consistent with ammoniumnitrogen.And the mean of total nitrogen concentrationat thebasal,tillering,and jointing stages was reduced by 87.19%～93.87%(2015)and 76.93%～83.48%(2016), 69.74%～79.73%(2015)and 74.46%～87.52%(2016),94.43%～96.69%(2015)and 95.52%～96.57%(2016).RBB reduction treatments reduced the total nitrogen and ammonium nitrogen concentration in the early stage(basal and tilleringstage),and showed a decrease trend with the application amount decreased.However,there was not a uniform regularity ofnitrogen concentration in surface water between RBB reduction of 10% and 20% in 2015,20% and 30% in 2016.The resultsindicated that the application of RBB reduced the nitrogen loss risk in the paddy field in Taihuarea.And RBB rate with 189～ 216 kg/hm2 reduced the nitrogen concentration of surface water and nitrogen loss risk on the premise of ensuring rice yield.