The present research was performed for studying morphological variation and investigating the presence of relationship between molecular markers related tillering in some genotypes of bread wheat under the field farm and laboratory conditions. In the field experiment, three seed densities including, and seed per square meter as the main plot factor and also genotypes including the cultivars of Arta, Inia, Tajan, Darya, Shirudi, Golestan, Gonbad, Morvarid, Moghan and Line N--as sub plot factor at three replications were applied. Evaluating characteristics were included of the number of secondary spikes, the weight of main and secondary spikes, the contribution of main and secondary spikes, seed yield per plant and plot, length of main spike and the height of plant. The results of analysis of variance showed that genotypes had significant different on all investigating characteristic, while the effect of factor density was significant only for the weight of the spikes, yield per plant and plot and the length of main spike. None of the characteristic was not affected by the interaction of genotype density. Based on the results, density and genotype had important effect on seed yield of the genotypes, however the effect of genotype was more than density. Mean comparison of the genotypes showed that secondary spikes had more contribution in the grain yield. In molecular experiment, SSR marker namely Xgwm associated to gene tin (tiller inhibition gene) was tested. Evaluation of the PCR product of this marker showed that the presence of band with the size of to base per is relating to reduction that tillering was confirmed in cultivar Tajan, Shirudi, Golestan, Darya and Gonbad genotypes that their low number of spikes had already been proven. So the efficiency of tin marker was proved for screening wheat for tillering.