Abstarct: In order to study the effects of N on yield & yield components of winter wheat this experiment was conducted as a complete randomized block design with 12 treatments (11 fertilizer treatment + control) and 4 replication at farm research of shahrood university of technology. In 5 treatments the urea values equal to 50 , 150 , 200 and 250 kg.ha-1 were considered which in all treatments 50kg were added at sowing date and residue were added at jointing stage. In 3 treatments with 150,200 and 250kg.ha-1 urea , 50kg added at sowing date and 50kg added at the form of soil application at anthesis and the residue at jointing stage. In other 3 treatments, the value of 150,200 and 250kg.ha-1, urea were added at the same way that explained above, only in the anthesis stage the soil application replaced with foliar application. In this experiment the grain yield, total dry weight, 1000 seed weight, number of seeds per spikes, number of spiklet per spike, spike weight and number of spike per square meter, height, harvest index and spike length were evaluated. The results show that the effects of all fertilizer treatments on all traits were significant. The highest amount of grain yield and 1000 seed weight, harvest index, number of seeds per spikes and number of spiklet per spike were obtained with 250 kg.ha-1 urea in the form of foliar application. Also the greatest amounts of total dry weight, spike weight, number of spike per square meter and height and spike length were obtained from application of 250 kg.ha-1 urea with application of 200 kg.ha-1 urea at jointing stage.