Bacterial diseases of soybean has been recognized as a limiting factor of soybean production in Korea as it was estimated to cause around 10 percent of yield losses annually. The purpose of the study is to obtain information on the diseases through proving the kinds of pathogens and epidemiology, The wire brush method and multineedle appeared to be the best way of inoculation under all circumstances. Wire brush method, especially, was effective in shortening the incubation period and manifesting the lesion development by introducing more inoculum per unit of area. In case of spray inoculation it was necessary to apply a small amount(1 : 1,000) of wetting agent, twin-20, otherwise it was unabled to produce the diseases under field conditions. Two kinds of bacterial diseases caused by Pseudomonas glycinea and Xanthomonas phaseoli var. sljense were found from surveyed areas in Kore. Wild fire disease on soybean caused by Pseudomonas tabaci had not detectable during the experiment although there were several reports on the disease from other countries. when the pathogens were introduced into sterile soil, bacterial leaf blight pathogen could exsisted until 30 days while bacterial pustule pathogen survived only 4 days under the natural conditions of later June. Both bacteria, however, could produce the disease after more than 10 months period of storage in refrigerator when they were exsisted in infected plant tissues. In warehouse, non-temperature controlled, the bacteria lose their infectability within 6 months period from October to April even though they exsisted in infected tissues. Surface infested seeds with the pathogens could not produced the diseases on seedling stages of soybean plants when the seeds were planted in sterile soil after inoculation by dipping the seeds into bacterial suspensions, although germination was depressed by the pathogens when the seeds were planted on agar media.