Abstract: To study the differences of distribution pattern of Eupatorium adenophorum varies with three light level along roads,13 sites in different light level were selected along 4 roads(Among them there were two high-grade roads and two low-grade roads respectively)in the middle area of Yunnan,which was the invaded area of Eupatorium adenophorum.The following results were obtained:light level had a very significant effect on distribution pattern of Eupatorium adenophorum along roads(p 0.001);Eupatorium adenophorum might invade more seriously and farther in areas that had high light levels than those had medium or low light level.Plant communities adjacent to high-grade roads might be more invaded by Eupatorium adenophorum than those adjacent to low-grade roads.