Abstract: Wedelia chinensis(Os) Merr.is a common garden herb in South China. Thereis little weed within its community.The allelopathic effects of Wedelia chinensis aqueousextractions on seedling growth ofradish, mungbean,cucumber, riee and seed germinationof rice were tested. Comparied with the checks of aqueous extractsfrom other 7 piants. alleloDathic effects of Wedelia chinensis were the strongest. In addition, aqueous ex- tracts of the plant also showed its allelopathic effects on the germination and seed- ling growth of Alternanthera philoxeroides and Eragrostics cilianesis Highconcentration aqueous extracts had autotoxic effects on the germination and seedlinggrowth of Wedelia chinensis.The comparsion of allelopathic effects of the four organsand whole plant of Wedelia chinensis,the declining order was: leaf> stem>flower>whole plant > root.