[Objective] The paper was to screen the better extraction method for herbicidal active substances of Eupatorium adenophorum. [Method] Three common extraction methods, Soxhlet extraction, ultrasonic extraction and conventional extraction method, were used to prepare E. adenophorum extracts, and the herbicidal activity of E. adenophorum extracts extracted by 3 methods was studied by seed germination method. [Result] The extraction rate of Soxhlet extraction was the highest of (22.54±0.48)%, and the herbicidal activities of E. adenophorum extracted by Soxhlet extraction was relatively stronger. [Conclusion] Soxhlet extraction was the better extraction method for herbicidal active substances of E. adenophorum. [Objective] The paper was to screen the better extraction method for herbicidal active substances of Eupatorium adenophorum. [Method] Three common extraction methods, Soxhlet extraction, ultrasonic extraction and conventional extraction method, were used to prepare E. adenophorum extracts, and the herbicidal activity of E. adenophorum extracts extracted by 3 methods was studied by seed germination method. [Result] The extraction rate of Soxhlet extraction was the highest of (22.54 ± 0.48)%, and the herbicidal activities of E. adenophorus extracted by Soxhlet extraction was relatively stronger. [Conclusion] Soxhlet extraction was the better extraction method for herbicidal active substances of E. adenophorum.