Abstract:There is a close relationship between the amount of content of P and K in soil and the incidence of the disease. When the content of P in soil is high, the incidence of the disease would be slight. When the content of K in soil is high the incidence of the disease would be serious. Index of invasion is in a negative correlation with P/K based upon the results, 32P and 86Rb were used as radioisotope tracer in uptake by diseased twigs and leaves of Paulownia. Results indicated that the species which is resistant to the disease absorbed more K and less P than the species which is susceptible.