Laboratory tests were conducted to screen,purify and evaluate the potential herbicidal metabolites produced by five different Trichoderma species on preventing seed germination( SGe) and shoot / root growth( SGr / RGr) of weeds. The results showed that the inhibiting rates( IR,%) on SGe and SGr / RGr of seedlings with 10% and 20% diluted culture filtrates produced by the strain of Tr673 were significantly higher( P≤0. 05) compared to those produced by the strains of Tr319,Tr347,Tr324 and Tr85. Purification of the metabolites of Tr673 culture filtrate was achieved by using silica gel column chromatography,preparative highperformance liquid chromatography and other methods. Ninhydrin reaction of the hydrolysate and the negative response of purified compound suggested that this compound could be a type of peptaibols. The bioassay with purified compound( 62. 5 mg / L) of Tr673 showed that SGr / RGr rates( %) of the weeds were significantly( P≤0. 05) decreased compared to those with chemical herbicide-glyphosate. Laboratory tests were conducted to screen, purify and evaluate the potential herbicidal metabolites produced by five different Trichoderma species on preventing seed germination (SGe) and shoot / root growth (SGr / RGr) of weeds. The results showed that the inhibiting rates (IR, %) on SGe and SGr / RGr of seedlings with 10% and 20% diluted culture filtrates produced by the strain of Tr673 were significantly higher (P ≦ 0.05) compared to those produced by the strains of Tr319, Tr347, Tr324 and Tr85 Purification of the metabolites of Tr673 culture filtrate was achieved by using silica gel column chromatography, preparative highperformance liquid chromatography and other methods. Ninhydrin reaction of the hydrolysate and the negative response of purified compound suggests that this compound could be a type of peptaibols. bioassay with purified compound (62.5 mg / L) of Tr673 showed that SGr / RGr rates (%) of the weeds were significantly (P≤0. 05) decreased compared to those with che mical herbicide-glyphosate.