In order to investigate the effect of tillage system and nitrogen consumption on yield, yield components, protein percentage and determination of the most important effective component of wheat yield, a split plot experiment was carried out based on randomized complete block design with four replications in Gonbad-e-Kavous University farm in 2010-2011. In this experiment, tillage system as the main factor with three levels (none tillage, sub-soiler and mold board plow) and nitrogen amounts as the sub factor with four levels (0, 50, 100 and 150 kg/ha). The results showed that only 1000-grain weight was affected by tillage system. The maximum 1000-grain weight was obtained 42.31g from sub-soiler treatment. The effect of nitrogen consumption on plant height, number of spike per square meter, spike length, number of spikelet per spike, number of grain per spikelet, grain number per spike, grain yield, protein percentage and protein yield were significant. 1000-grain weight was not affected by nitrogen treatment. The minimum plant height, number of spike per square meter, spike length, number of spikelet per spike, grain number per spikelet, grain number per spike, grain yield, protein percentage and protein yield belonged to no nitrogen application. All traits were increased by increasing of nitrogen consumption except 1000-grain weight, so that the maximum traits were obtained at 150 kg nitrogen/ha application. Nitrogen application was more effective than tillage system on quantity and quality traits of wheat. The results of path analysis showed that the direct effect of grain number per spike on grain yield was more than other variables. Therefore, grain number per spike was the most important component in grain yield.