In the process of identification of Streptomyces species, some important additional physiological and biochemoical tests were employed. Not all authors used all these parameters for characterization of species and in differentiating from other species which are considered to be significant secondary group characters for the identification and classification of new isolates belonging to actinomycete group. The following additional tests are conducted and observed their effect on growth: i) Effect of carbon source ii) Effect of nitrogen source iii) Effect of inhibitory chemical compounds and iv) Effect of antibiotics