Abstract: The study of anthorcnose of Camellia oleifera is of economic and scientific importance. The present paper deals with the effects of toxin produced by Colletotrichum camelliae on PAL, which is a determinant enzyme in secondary metabolism and is closely related to disease resistance.Colletoribhum camelliae secretes a toxic substance into culture medium. The toxic substance causes tomato seedling to wilt and induces Lession fleck on leaves of Camellia oleifera. PAL activities from leaves, callus and suspension cells of Camellia oleifera are stimulated increasingly. The time course in increased PAL activities is the same between susceptible and resistant forms, but the increased extent in resistance is equivalent to 2.4—fold in susceptible form during 44 hr. The increase in PAL activity is the result from activation of inactived-enzyme molecular and re-synthesed enzyme protein. The possible roles of toxin produced by C. camelliae in resistance and possibility to take highness in PAL activity which is induced by the toxin for a biochemical indicator of resistance are discussed.