In order to determine the effects of various corn planting densities and mechanical management methods on weeds, this experiment was carried out at the research farm of Islamic Azad University of Takestan, Iran. A randomized complete block design (RCBD) in a factorial experimental design with four replications was used. Experimental treatments were density factor (including recommended density, 25 and 50% more than recommended one) and mechanical weed control (including two weedings, one weeding, without weeding, one cultivator at corn 25 cm height, and two cultivators at corn 35 cm height). According to the results, corn density and mechanical weed control had significant effect on the reduction of weeds biomass and density, in most cases. Thereby, among mechanical weed control, twice weeding and twice cultivator were the best, and without weeding and once weeding were the worst treatments, respectively. Also, maximum corn biological yield was obtained when twice weeding and twice cultivator was used. Furthermore, results showed that the best reduction of weeds density and biomass were achieved in density of 50% more than recommended one, but among corn traits, the most effective corn density was the recommended one.