Abstract: The experiment was carried out at the Department of Animal Nutrition, Bangladesh Agricultural University, Mymensingh, to study the effects of different doses of nitrogen (N) fertilizer on yields and chemical composition of Zamboo grass. The fodder was cultivated at 4 levels of N fertilizer viz., 0, 50, 100 and 150 kg urea ha-1 in a completely randomized design having four replications in each treatment. The unit plot size of each replicate was 4×4 m. The fodder was harvested at the pre flowering stage (68 days after sowing) for first cutting and again 40 days after first cutting. The proximate components of the fodder for each plot were determined at the laboratory, Department of Animal Nutrition. The results of the study showed that the total yields (t ha-1) of Zamboo grass on fresh basis were 11.08, 15.63, 22.35 and 26.72 in the first cuttings and 7.94, 12.24, 16.65 and 22.41 in the second cutting using 0, 50, 100 and 150 kg urea ha-1, respectively. The total dry matter (DM) yield of fodder for first cutting at the treatment levels of 0, 50, 100 and 150 kg urea ha-1 were found to be 1.85, 2.75, 3.66 and 4.60 t ha-1 and those in second cutting were 0.67, 2.13, 3.08 and 3.97 t ha-1, respectively. Total yields of fodder green as well as DM basis in both cutting progressively and significantly increased with the increasing levels of N fertilizer doses. Similarly crude protein (CP), crude fiber (CF) and ether extract (EE) yields (t ha-1) were increased with increasing fertilizer doses. The green fodder as well as DM yields and percent of different proximate components of each treatment were higher in the first cutting than that of the second cutting except CF. The DM percent of the fodder was almost similar for different fertilizer treatments in both cutting. Among the various proximate components, CP, CF and EE percent increased by increasing the N fertilizer doses while ash percentage decreased.