In order to study yield and yield components of wheat under the influence of genotypes and planting date under rainfed conditions, an experiment was carried out in the Agricultural Research Station of Gonbad-e-Kavous in 2010-2011. The experiment was arranged in a factorial design based on randomized complete block design with five genotypes (Zagross, Koohdasht, Morvarid, Lain 17 and N-80-19) and four planting dates (17 Des. 2010, 3 Jan. 2011, 20 Jan. 2011, and 6 Feb. 2011) with three replications. The results revealed that biological yield, grain yield and yield components (except for seed weight) decreased with a delay in planting, but harvest index increased. The highest (480.9 g/m²) and lowest (337.6 g/m²) grain yield was produced at the first and late planting date, respectively in such a way that in every day delay in planting date, the yield was decreased (2.81 g/m²) i.e. 0.58 percent. Koohdasht and N-80-19 produced the highest and lowest grain yield and biological yield, respectively. There was a positive and significant correlation between grain yield and biological yield (r=0.94^**) but it did not have any significant correlation with harvest index. Generally, yield reduction happened not only due to the decrease of the number of seed per spikes and the number of spikes/m², as a result of delaying in planting date but also due to the reduction of growth period.