Abstract: Marine antagonistic actinomycete strain Streptomyces rochei (MTCC 10109) was isolated from the sea water samples of Visakhapatnam coast of Bay of Bengal by serial dilution method. The aim of study was identification and characterization by its morphological, physiological and biochemical studies and deposited to Microbial Type Culture Collection and Gene bank, IMTECH, Chandigarh, India with accession number is MTCC 10109. It was a gram-positive, very long rods and filamentous organism, consisting of sporangia with spores observed by using cover-slip method and evaluated by phase contrast microscopes. It was capable to produce yellow pigments and possessing an earthy characteristic odour and exhibited optimum growth under aerobic conditions at temperature 30°C, pH at 7.0 and sodium chloride level at 2% (w/v). So, it was considered as a mesophillic, alkaliphillic and moderate salt tolerance in nature. The isolate showed difference in the carbon utilization, able to utilize all studied carbon sources, except xylose, adonitol, sorbitol, inositol and raffinose and showed positive results to methyl red test, nitrate reduction test, citrate utilization, urea hydrolysis, cytochrome oxidase, catalase test, gelatin hydrolysis, arginine dihydrolase, tween-60, tween-80 and esculin. It was exhibited broad antagonistic spectrum against all tested selective human pathogenic fungi and bacteria and its activity measured by zone of inhibition (mm), by agar well diffusion method. Among all the studied pathogens, Candida tropicana, Staphylococcus aureus and Escherichia coli were the most sensitive organisms from selective human test pathogens of fungi, gram-positive and gram-negative microorganisms respectively. Altogether, the results indicated that the natural marine environment is also good sources for isolation of novel varieties of antagonistic Streptomyces.