Abstract: Parasitic plants are an important component of terrestrial ecosystems, and widely distributed in most terrestrial ecosystems. They totally or partially depend on the host plants to absorb organic and/or mineral nutrients and water to complete their life cycle. Parasitic plants not only have direct effects on their host plants, but also give influence on the whole plant community via affecting the competition between their host and non-host plants. At individual level, parasit
ic plants generally show negative effects on the growth of their host plants, and often result in severe financial losses. As a result, the control of parasitic plants has been the focus of relevant research. At community level, however, parasitic plants have positive effects on promoting biodiversity. By this token, parasitic plants have a potential to be used in plant community engineering. Whether to control or to utilize parasites, it is essential to understand their biological traits. This paper reviewed the biological traits of parasitic plants, including parasitism type, host range and preference, host recognition, and haustoria formation and functions. Also, the impacts of parasitic plants on their hosts and on the community structure where the host plants occurred were discussed. The research gaps in relevant fields were pointed out, and the possible research topics were suggested.

Key words: Leymus chinensis grassland, Soil, Catalase activity, Environmental factors