[ Objective] The aim was to explore effects of thymol on the plant pathogenic microorganism. [ Method] We studied the inhibitory activity of thymol on 13 kinds of pathogenic microorganism by cup-plate method. [ Result] The thymol couldeffectively inhibit the growth of tested kinds of bacteria, and could inhibit significantly four kinds of plant disease fungus,which were Fusarium moniliforme Sheldon,Fusarium oxysporum Schlecht,Colletorichum orbiculare and Sclerotinia sclerotiorum. The bacteriostatic effect was positive correlation to the concent...