Abstract: To study the effect of commercially used disinfectants on resting spores of club root and conidia of Alternaria, five chemicals including 70% alcohol, 50% alcohol, 35% alcohol, Meliseptol and Soft-man were respectively sprayed on the spore and conidia suspension of Plasmodiophora brassicae and Alternaria brassicicola. Distilled water was used as a control. As parameters of resting spore and conidia viability, the proportion of dead spores of Plasmodiophora brassicae and germinated conidia of Alternaria brassicicola were used. As a result, all of the five chemicals had remarkable effect on both pathogens comparing with the control. By averaging the proportion of dead spores of each treatment, the increasing sequence ranged as control（26.6%）<50% alcohol (50.5%）<35% alcohol（53.3%）<70% alcohol （65.2%）< Softa-man（91.3%）< Meliseptol（94.3%）. Whereas, by averaging the proportion of germinated conidia of each treatment, the decreasing sequence ranged as control（28.3%）?35% alcohol (22.8%）?50% alcohol（22.2%）?70% alcohol (9.9%）?Softa-man（7.6%）?Meliseptol（0.7%）.The result suggested that both commercially disinfectants Meliseptol and Softa-man nearly fully destroy the sprore or conidia of pathogen, and 70% alcohol could destroy most of the pathogen, while 50% alcohol and 35% alcohol nearly could not destroy the pathogen.