Abstract：In this study，the active materials were extracted from Aucklandia lappa Decne，Syzygium aromaticum，Cinnamomum cassia and Rheum palmatum by ultrasound assisted extraction（UAE）．Fusarium oxysporium f.?sp.?cucumerinum and Fusarium oxysporum f.?sp.?Niveum were inhibited by 4 plant extracts and their mixtures，and the inhibition rates were measured by the growth rate method．The results showed that mycelial growth was significantly inhibited by all of these extracts，and the antibacterial effect was increased significantly when the extra concentration was increasing．Less minimum inhibitory concentration（MIC）and better inhibitory effect can be acquired by suitable mixing ratio of these extracts．The mixtures of extracts of Aucklandia lappa Decne and Cinnamomum cassia had better antibacterial effect than their single effects，and the optimum ratio was 3∶1．The antibacterial effects of mixture of Cinnamomum cassia and Syzygium aromaticum（optimum ratio is 1∶2）and mixture of Aucklandia lappa Decne and Rheum palmatum（optimum ratio is 2∶1）were also stronger．
