Abstract: The polarographic method for streptomycin-assay using 3% tetramethylammo- nium hydroxide as supporting electrolyte has been reported by Levy,Schwed and Sackett.After a series of experiments we found that streptomycin in a solution of potassium chloride,ammonium hydroxide or sodium hydroxide showed also polarographic waves.However,the wave obtained in sodium hydroxide solution was better defined than the others.In order to obtain a well-defined and reproducible polarographic wave of streptomycin in sodium hydroxide solution,different experimental conditions such as concentration,temperature etc.,were studied. The results are given in three tables and also shown graphically in three figures in this paper.