Abstract: Effect of N fertilization(i.e.,0,120,180and 240kg·hm-2)and the transplanting density(i.e.,14.1 ×104,18.4×104 and 21.5×104 holes.km-2)on the yield and yield components for super hybrid rice,Yi You 673,were studied in the field experiments conducted in 2012.N fertilizer was found to affect more significantly on the panicle number,grain number per panicle and seed-setting rate than the 1000-grain weight.The effect of transplanting density on the panicle number was higher than those on the grain number per panicle,seed-setting rate and 1000-grain weight.When 180kg·hm-2 N and a transplanting density about 21.5×104 holes.km-2 in the medium-fertility field were applied for the cultivation of Yi You 673m,its yield could be maximized.