In order to study the effects of nitrogen levels and its application time on fresh, dry matter and agronomic traits of forage sorghum Var. Speed-Feed, an experiment was carried out as a factorial design in a randomized complete block design with three replications in Agricultural and Natural Resources Research Station of Khoy during 2009 growing season. Four levels of nitrogen (60,120, 180 and 240 kg [ha.sup.-1]) were applied with four nitrogen application times ([T.sub.1] = all applications before sowing, [T.sub.2]=1/2 before sowing + 1/2 beginning of the second harvest, [T.sub.3]= 1/4 before sowing + 1/4 in 30-40 cm stem height of the first harvest + 1/4 beginning of the second harvest + 1/4 in 30-40 cm stem height of the second harvest, [T.sub.4]=1/gbefore sowing + 1/g in 30-40 cm stem height + 1/gin swelling of the flag leaf sheath in the first harvest +1/gbeginning of the second harvest + 1/6 in swelling of the flag leaf sheath in the second harvest). The maximum total dry and fresh fodder matter and protein yield were obtained by the 240 kg [ha.sup.-1] of the nitrogen application(92.06, 20.16 and 2.22 t/ha, respectively) while, there was not a significant difference with the application of 180 kg ha-1. The maximum total fresh and dry fodder matter were obtained by the [T.sub.4] application times (89.28 and 19.62 t/ha, respectively)while, there was not significant difference with [T.sub.2] and [T.sub.3]. The highest correlations of dry fodder yield were observed with stem height and fresh fodder yield ([r=0.686.sup.**] and [r=0.872.sup.**], respectively). Regarding to being non-significant differences between amounts of 180 and 240 kg [ha.sup.-1], application of 180 kg [ha.sup.-1] nitrogen with [T.sub.4] times is recommended. It can be concluded that, one-stage application of nitrogen fertilizer could cause nutrient loss in soil through sublimation and leaching. Key words: Application time, forage sorghum, nitrogen, yield.