The study was carried out to optimize in vitro culture conditions of increasing Streptomyces spp. growth rate. Physical and chemical conditions such as temperature, pH, salinity, C and N sources were performed on 3 strains of Streptomyces spp. including TV1.4, CM2.4 and DH3.4 in m-ISP2 C medium. After that, optimal C and N sources were selected to determine the optimal concentration for the growth of the studied bacterial strains. The experiments were designed in test tubes containing m-ISP2 medium with three replications. Bacterial growth was assessed by measuring optical density 600nm. The results showed that the optimal condition for TV1.4 strain grow best at pH 7, temperature 30℃, salinity 10‰, starch 2%, tryptone 2%. CM2.4 strain grow best at pH 8, temperature 40℃, salinity 10‰, starch 1%, tryptone 1% and strain DH3.4 grow well at pH 7, temperature 35℃, salinity 10‰, starch 1% and tryptone at 2% concentration. Among the 3 studied strains, Streptomyces TV1.4 was the best selected bacteria strain.