ABSTRACT The paper aimed to inhibit evaluate the effects of some salts as natural products on postharvest diseases of sweet pepper fruits under the laboratory conditions and evaluate their effects on the development and suppression of these diseases. To achieve these aims, four different salts i.e. sodium carbonate, sodium bicarbonate, potassium nitrate and calcium chloride was applied at four concentrations, 1, 2, 3 and 4% (w/v). Salt solutions were tested on the mycelial growth and spore germination of Ulocladium chartarum, Aspergillus niger, Fusarium semitectum and Geotrichum candidum. Seven days post incubation, mycelial growth of the tested fungi were completely inhibited by the used salt solutions. Generally, the obtained results indicate a clear impact for most used salts solutions especially sodium salts. Finally, the optimum concentrations of salts under the experiments study conditions for inhibiting of growth of Ulocladium chartarum, Aspergillus niger, Fusarium semitectum, and its spores. Geotrichum candidum were 4, 3, 3, 3% (w/v) for sodium carbonate, sodium bicarbonate, potassium nitrate and calcium chloride, respectively.