A two years field study was conducted to evaluate the effect of response of two sweet sorghum cultivars to different sources and time of nitrogen application during 2009 and 2010 at experimental farm Faculty of Agriculture, South Valley University at Qena Governorate, Egypt. Two cultivars viz. Tracy and Honey and six combination of source and application time of nitrogen fertilizes viz. ammonium sulphate, 20.5% N in two equal doses (T1) and in three equal doses (T2), ammonium nitrate, 33.5% N in two equal doses (T3) and in three equal doses (T4), urea, 46.5% N in two equal doses (T5) and in three equal doses (T6) were tested in the study. The experiment was laid out in split plot design with cultivars in main plots and nitrogen fertilizers in sub-plots. Among sweet sorghum cultivars, cv Honey had the highest stalk height, stalk diameter, number of internodes per stalk, Brix value, sucrose content, apparent purity percentage and stalk and forage (leaves) yields and lowest reducing sugar content. Application of T4 gave the highest value of the above measurements and lowest reducing sugar content. Cultivar and nitrogen treatments interaction was significant on stalk and forage yields as well as reducing sugar content. The highest stalk and forage yields and lowest reducing sugar content were obtained by planting cv Honey and application of ammonium nitrate in three equal doses (at planting , 4 leaf stage and booting). Plant height, stalk diameter, forage yield, brix and sucrose were positively and strongly correlated with stalk yield.