Greenhouse and field experiments were conducted in 2008 and 2009 to study the effect of calcium sulfate (CaCO₄) concentrations at 0.0., 200, 400, and 800 ppm by using two applied methods or/and seed soaking and plant sprayer on incidence of sesame and sunflower charcoal rot disease caused by Macrophomina phaseolina Tassi (Goid). Treated with CaCO₄ showed a significant reduction onthe percentage of linar growth and number of sclerotial formation of M. phaseolina isolates which isolated from sesame and sunflower plants. The highest effect on the reduction of M. phaseolina linar growthand number of sclerotial formationwasrecorded withCaSO₄ at 400 ppm. Using both of soaking and sprayer with CaSO₄ whether separately or together gave a significant decrease of charcoal rot and incidence of survival plants compared with control,while the effect of CaSO₄ on reducing of diseases incidence increased with increasing of their concentration under greenhouse and field conditions. Use of CaSO₄ at 800 ppm as soaking and sprayer method together recorded the highest effect on decreasing of charcoal rot as well as increasing total seed yield of sesame and sunflower plants during the two growing seasons 2008 and 2009.