By the improvement of the quantity of Endophytic bacteria,the antagonism of Endophytic bacteria isolated from cucumber and inoculated into cucumber against Fusarium oxysporum f.sp.were studied.The result of potted experiment and filed test showed that the effect of Fusarium oxysporum f.sp.on cucumber with mixed liquid of 6 strains bacteria were equal to the effect of thiophanate-methy.The effect of mixed liquid of 3 strains bacteria was poor.