An attempt was made to develop the artificial inoculation method of seed transmission experiments. Injection of Xanthomonas campestris pv. glycines through seed mycopyle at 103 and 105 cfu/seed gave 100% seed transmission with no effect on seed germination. When seeds derived from artificially inoculated soybean plants were used, the rate of seed transmission was dependent on the disease severity of parent plants. Seed transmission ratio was higher with seeds taken from plants inoculated 3 times than those inoculated 2 and 1 times respectively. The administration of the vacuum pump (20 lb/inch2) for 10, 20 and 30 min after soaking seeds in bacterial suspenssion at 106 cfu/ml revealed no difference in percent seed transmission. Furthermore, this method significantly reduced seed germination.