Planting high quality seed is important in efficient soybean production system. One factor that reduces seed quality is mechanical damage. Soybean seed is very fragile and susceptible to mechanical damage that occurs at harvest, processing, drying and handling. Care should be taken to prevent seed damage and injuries during processing because mechanical damage reduces seed germination and vigor. So this research was conducted to evaluate the effect of mechanical damage on soybean seeds germination and vigor after processing. This study was completed as factorial on the basis of completely randomized design with three replications. The treatments were cultivar at three levels (Sahar, Williams and D.P.X) and the moisture percentage at three levels (12-14, 14-16 and 16-18 percent) and the measured characters were mechanical damage percentage and germination percentage. Also the electrical conductivity test and accelerated aging test were conducted to evaluate seed vigor. The variance analysis results showed there was a significant difference in mechanical damage and germination percentage between cultivars in a way that the cultivar of Sahar had the maximum mechanical damage and the highest amount of electrical conductivity and minimum germination percentage. Also there was a significant difference between three moisture levels in measured characters. The moisture of 12-14 percent had the lowest amount of mechanical damage and maximum germination percentage and 16-18 percent had the highest mechanical damage and the lowest germination ability.