Juice was squeezed from the root，basal part of stem and leaf of fresh Allium tuberosum and Allium fistulosum. With the methods of plate confrontation and addition，its inhibition on mycelium growth and spore germination of Fusarium oxysporum f.sp.cubense Race 4 were studied. The results showed juice from different parts of both Allium tuberosum and Allium fistulosum with various concentrations had some inhibition to the mycelium growth of Fusarium oxysporum f.sp.cubense after being treated for seventy two hours with plate confrontation. The inhibition effect of Allium tuberosum stem juice was 63.18%，on the top of the list. With the method of addition，the inhibition of Allium tuberosum juice was highly significant，all over 94%. Most important of all，the inhibition effect of stem was the best，up to 100%.The inhibition of Allium fistulosum leaf juice was also 100%.The spore germination rate was 0 as the juice concentration was over 55% for all parts of the two plants.