Abstract:Alternanthera philoxeroides (Mart.) Griseb.is one of the most notorious invasive weeds and has been introduced to the regions with warm to subtropical humid climates worldwide.We tested bioassay in laboratory to ascertain the effect of Humulus scandens (Lour.) Merr.on vegative growth and allelopathic potential of the invasive species.In this study,the effect on the invasive species is determined by water extract of different organs (belowground and aboveground organs) from H.scandens plants.The main purpose of this study was to find the relationship between H.scandens and A.philoxeroides’s replacement control.The results as follow:(1)Compared with the extract of aboveground organs,the inhibition of allelopathy from belowground organs was stronger than that from aboveground parts at the same concentration.(2)The organs of H.scandens has different function on the leaf area of host plants and the leaf area were reduced to 40.21%,when the rhizome of host plants were applied the extract from the underground organs of H.scandens.(3)The extracts of different organs had little inhibitory effect on the node number of ramets,however,the extracts significantly inhabited the number of ramets which was 25% lower than the contrasts.（4）The water extracts from belowground organs inhabited ramets length of the invasive species.The present study suggests that H.scandens could be used as biological alternative material to manage A.philoxeroides invasion.