Abstract: Based on growth rate method and Petri dishes filter paper method, extracts of stem and leaf from Chrysanthemum indicum L. and extracts of its rhizosphere soil were tested for their allelopathic effects on seed germination and seeding growth of Atractylodis macrocephala Koidz. , and on the development of Sclerotium rolfsii Sacc.. The mycelium growth was significantly restrained at the concentration of 0.5 g/mL of the aqueous extract of stem and leaf, at the concentration of 0.125 g/mL of the ethanol extract of stem and leaf, and at the concentration of 0.25 g/mL of the aqueous extract and the concentration of 0.125 g/mL of the ethanol extract of its rhizosphere soil from Chrysanthemum indicum L, and the stimulative rates were enhanced with the increasing concentration. Seed germination and seedling growth were inhibited at 0.5 g/mL of the aqueous extract of stem and leaf, while ethanol extract of stem and leaf showed less inhibitory. It suggested that allelochemicals in the ethanol extract of stem and leaf from C. indicum L. contributed the inhibitory effects on S. rolfsii, and couldn't effectively deal with seed germination and seedling growth. The results provide a new experimental basis that ethanol extract of stem and leaf from C. indicum L. will be used to develop a new botanical fungicide to deal with soil-borne diseases in A. macrocephala.