Abstract:It has been proved that penicillin spray on Ligusticum chuanxiong can contribute to the growth of the plant inthe following ways:cutting down the tissue water potential,strengtkening the capability of sucking moisture,in-creasing the contents of chlorophyll and restraining its degradation to facilitate the formation of photosyntheticcompounds,enriching the nutrition root and increasing the root-shoot ratio. All these help to keep the stem tuber-ot under 5%so as to guarantee higher economic yield of the plant.