In order to evaluate the density and Mungbean management effects on seed yield of Sesame and suppression of weeds, an experiment was done in research field of Sari university of Agricultural and Natural Resources in 2015, in randomized complete block design with 3 replications. Treatments included 3 level of Mungbean density (5, 10 and 15 plant.m-2), 3 level of Mungbean management (no management, cut and putting in the sides of sesame, and spraying with Paraquat herbicide at half recommended dose), and 2 check treatments (no cover crop at weed free and weed infested at full season). The results showed that sesame seed yield at full season weed infested reduced by 58% compared with weed free plot. Cutting cover crop management at 5, 10 and 15 plant.m-2 densities, caused to increase seed yield by 84, 96, and 120% compared with weed infested plot. The highest density and dry weight of broad leaf and grassy weeds were observed at full season weed infested (at no cover crop plot). Dry weight of grassy weeds at no management, cutting and spraying with herbicide at 10 Mungbean plant.m-2 reduced by 83, 86 and 89% compared with no cover crop at weed infested, respectively. Finally, the importance of sustainable agriculture can be recommended Mungbean cover crop (density of 15 plant.m-2) with cut management to improve seed yield of Sesame and suppression of weeds.