Abstract: Arceuthobium chinense Lecomte is confizied to and common on Keteleeria evelvniana Mast,throughout the range of this tree in the Southwestern China*This parasite causes extensive damage to the Keteleeria evelyniana in both pure and mixed stands.The incidence of infected trees may be upto 70 per cent or more in certain localities and its utmost disease index may be attained to 68.89 per cent.The morphological characteristics and the process of disease cycle were studied.The control measures for checking the development of this parasite are recommended.