The purpose of this work was to study whether the abnormal starch accumulation in the leaves of the paulownia tree affected by witches'-broom would occurred. The experiment was designed to compare the soluble sugars of the leaves of the diseased tree with that of the healthy. Sugars in the leaves were determined by paper chromatograph. The results were as follows: 1. It was found that the soluble sugars in both the leaves of the healthy and diseased tree were consisted of glucose, fructose and sucrose, and no other sugars were detected in both cases. 2. The old leaves of diseased tree had a higher soluble sugar content than that of young ones and it was the same tendency in the case of the healthy tree. 3. The diseased tree had a higher content of clucose, fructose and sucrose in its leaves sampled both in the morning and in the evening than the leaves of healthy plant. It was concluded that the existence of the excess sugar in the leaves of the infected tree was due to the inhibition of sugar translocation from leaf.