To study the antimicrobial activity of streptomycetes isolated from marine soil sample in Tamil Nadu . The most potential isolate was identified based on its morphological, cultural, biochemical features and also confirmed by 16s rRNA partial gene sequencing. A total of 50 streptomycetes were subjected to primary screening by cross streak method against Gram-positive  and Gram-negative bacteria and also by  human and plant  pathogenic   fungi.  Putative isolate was  subjected to secondary screening by agar well diffusion method to further test the capabilities of primarily screened organisms. The antimicrobial  substances were extracted with ethyl acetate from active strain  by solvent extraction method. The active  isolate showed more active  against Klebsiella pneumoniae  and  candida glabrata. The most potential isolate was identified as Streptomyces coelicolor Strain SU6  (JQ828940). The observations from this study suggest that Streptomyces isolated from marine  environment may be potentially used for extracting novel antibiotics for treating both bacterial and  fungal infections in human.