Parthenium hysterophorus L. (Asteraceae) (tribe: Heliantheae), is an erect and muchrnbranched annual or ephemeral herb, known for its notorious role as environmental,rnmedical, and agricultural hazards. It invade large areas globally and threatening nativernbiodiversity. P.hysterophonrus is believed to have been introduced to Ethiopia in 1988 atrnthe Eastern part of the country (Deredwa and Harargie). The study was conducted inrnKombolcha city administration (KCA), South Wollo, Ethiopia. Since its introduction tornthe study area (KCA), parthenium weed has been spread in an alarming rate in the ruralrnareas. The main objective of this study is to identify and describe the distribution andrnecological impacts of the invasive species P. hysterophorus and to create awareness tornthe residents on its negative impacts in the ecosystem and biodiversity. The results of thernresearch suggested that parthenium weed have been distributed largely in uncultivatedrnareas, road sides, grazing areas, riversides and farm areas respectively. The impact ofrnP.hysterophoruson other plants is investigated by comparing plant species grown inrnassociation with parthenium and plant species grown in the absence of parthenium.rnQuedrats were used to identify the diversity of species in parthenium infested areas. Arntotal of 37 species were identified and the diversity of species in the infested areas ofrndifferent samples sites was computed using Shannonâ€™s diversity index. The result showedrnthat the diversity of species in parthenum infested areas is low. Hence, creating properrnawareness to the residents particularly farmers in the study area on its distribution andrnnegative impacts would be the best option to control further invasion of new valuablernlands by P.hysterphorus