Pathogens of fire blight can survive for a long time on pruning tools, etc., and fire blight can be spread through agricultural implements. In particular, in Korea, pruning is frequently performed to remove flowers, immature fruits, and succulent shoots, and this farm work is known to be a major factor of the spread of fire blight. Therefore, in this study, in order to completely sterilize pathogens on pruning shears, we verified the disinfection effect of disinfectants distributed domestically and used them to identify an effective disinfection method. When disinfecting by immersion after inoculating Erwinia amylovora TS3128 on the scissor blade, 70% ethanol and 1% and 0.2% sodium hypochlorite sterilized immediately 10 sec after immersion, while 30% chlorine dioxide showed little disinfection effect. When disinfecting by spraying, 70% ethanol sterilized bacteria 1 sec after spraying, but 1% and 0.2% sodium hypochlorite disinfected bacteria after 10 and 60 sec, respectively. After cutting the naturally disease occurring branches five and 100 times, the bacteria were not hardly sterilized in immersion treatment in 70% ethanol for 30 sec but perfectly disinfected over 60 sec. Considering these results, pruning shears should be disinfected by frequently immersing them in 70% ethanol for at least 60 sec during pruning work in the field.