Abstract: Digitaria sanguinalis as a reference target, the sensitivity of Echinochloa crusgalli was tested by 96-well plate assay with agar solution and small potted method. The comparison of herbicidal activities of herbicide standard compound, the fermentation broth of herbicide standard strain from fungi and actinomycetes was carried out by 96-well plate assay; The comparison of herbicidal activities of the fermentation broth of standard strain of fungi and actinomycetes was carried out by small potted method. The results showed that the sensitivity of Echinochloa crusgalli in 96-well plate assay was poor, especially not suitable for the screening of microbial herbicidal against Echinochloa crusgalli; The sensitivity of Echinochloa crusgalli and Digitaria sanguinalis in small potted method was similar, which was suitable for the microbial herbicide screening against Echinochloa crusgalli, with the outstanding advantages of high stability, strong resistance to microbial pollution, simple operation and so on; In view of the low sensitivity of Echinochloa crusgalli in herbicide screening, the method of selecting appropriate seedling stage was optimized.

Key words: Echinochloa crusgalli, herbicidal activity, microbial herbicide, monocotyledons