Woolly cupgrass (Eriochloa villosa /Thunb./ Kunth) is a common weed in East Asia and North America. This weed plant spreading quickly in Europa. There are several reasons for the successfulness, especially its germination properties. As other Panicoideae species contain benzoxazinoids it was supposed that woolly cupgrass also contains these chemicals. For this reason the benzoxazinoid content of plants at the stage of flowering was investigated. As it was supposed, woolly cupgrass contain benzoxazinoids, which is a novel occurrence of these chemicals in Poaceae family.