The tolerance of Fusarium oxysporum on formic acid, acetic acid, furfural, vanillin and catechol, which are hydrolysis inhibitor, during ethanol fermentation process was investigated by shake flask method. The results showed that the order of sensitivity to various inhibitors for Fusarium oxysporum was formic acid, acetic acid, vanillin, catechol and furfural during ethanol fermentation. The production of ethanol was similar with that of the control when the acid concentration was 0.6g/L at pH value 6.5 of acetic acid and pH value 7.5 of formic acid, respectively. Low concentrations of formic acid and acetic acid promoted cell growth, but high concentrations inhibited cell growth. And the inhibitory effect of vanillin, catechol and furfural on cell growth was stronger than that of the formic acid and acetic acid. The tolerance of Fusarium oxysporum for a single inhibitor was stronger than that for mixed inhibitor. The ethanol production was 78% of the control when the concentrations of formic acid, acetic acid, vanillin and catechol were 0.05g/L, respectively. 