A diseased camphor tree suspected to be caused by virus was found in Ube City of Yamaguti Prefecture. A similar disease, as far as the writers know, is likely to exist also in Miyazaki Prefecture. The diseased tree with slender twigs shows bad growth. The leaves are generally small in size and deformed. The mosaic symptom is distinctly shown. The pH value of the diseased leaves hardly differs from that of the normal. The detached leaves of the diseased more promptly lose the water content than those of the healthy, though the water absorption of the diseased is weaker in action. The diagnosis is possible according to the copper sulphate reaction proposed by the senior writer.