Abstarct: Nowadays, irregular consuming fertilizers and environmental pollutants cause many researchers and farmers are finding ways to reduce the use of chemical fertilizers to produce healthy products. The use of beneficial soil products such as growth promoting bacteria, suitable substitutes for improving soil fertility, increasing plant nutrient absorption and plant health are among the most important scientific methods to help soil stability and prevent the risk of chemical contaminants in the soil environment. In this study, in order to identify and introduce Streptomyces strains as bio-fertilizer for cucumber and tomato, experiments were conducted to evaluate the effect of growth promoting Streptomyces strains on some vegetative and productive of cucumber and tomato in greenhouse of Biotechnology Research Institute of Iran. The experiment was conducted as a factorial design in a completely randomized design with four fertilizer levels (0, 75, 50, 100%) and three replications for each. The results showed that co cultivation of cucumber seedlings with ss12 and ss14 strains and 75% of NPK fertilizer increased some important characters such as fruit yield, fruit dry matter and root dry weight and ty17 strain with the same level NPK caused to increase yield in tomato. The other characters such as glucose, chlorophyll, carotenoids, nitrogen, phosphorus and potassium and molecular characters confirmed mentioned results. Streptomyces strains at different levels of fertilizer had different effects on different traits in cucumber and tomato. Then, using these strain can help us to decrease at least 25% NPK fertilizer and improve the yield.