The surfaces of aerial plant provide a habitat for epiphitic microorganisms many of which are capable of influencing the growth of pathogens. In this study, fluctuation of bacterial population occurring in different growth stages of soybean leaves (Glycine max L Merrill) was examined using the dilution plate method. Three culture media were applied; invariably, the numbers of bacteria increased with increasing plant age. The total number of bacteria living on the detached leaves were ten times higher than leaves surfaces of soybean Asgrow 3127 (Group III). One hundred and seventy-five heterotrophic bacteria were obtained from both the phyllosphere and litter of the plant. Of these, fifty-one microorganisms (29%) were classified as members of the genus Bacillus; the remainder were mainly members of the irregular, nonsporing, Gram positive rods (coryneform bacteria). Approximately 52% of the total coryneform bacteria isolated was found to belong to the following two clusters: Arthrobacter and Corynebacterium. There were few Pseudomonas strains and 75% of the total isolated bacteria were able to grow in N-poor culture medium.