Abstract: Weeds is very harmful to the growth of crops，and the utilization of herbicides will lead to environmental poilution and devdopment of herbicide resistance in weeds．Allelopathy among plants is an effective way to control weeds．Weeds germination and growth are suppressed by allelochemicals released from smothering plants and environmental competition with smothering plants．In addition，the rdease of allelochemicals can be influenced by the measurements of rotation，tillage and other ways，which leads to different levels of weeds suppression．Breeding for smothering plants which posses allelopathic potentials is the most effective way to alleviate or eliminate adverse effects of weeds，which can incorporate allelopathic characteristics into plants to suppress weeds．