In order to study the feeding value of Broussonetia kazinoki, Siebold, the investigation on its characteristics and the feeding trial were carried out from April, 1974 to October, 1984. The growth of the tree was accelerated from age of 3 year. Green leaf and rhytidone was lower in C. protein content, but higher in c. fiber content than fallen leaf and leaf before fallen. Most of amino acids were higher in leaf fallen, except for cystine and aspartic acid, than in fallen leaf. The results obtained from the feeding trial indicated that the supplementation of Broussonetia kazinoki, Siebold to the growing-finishing pig diet resulted in improved weight gain (p$lt;0.05), feed conversion (p$lt;0.05) and feed cost per ㎏ gain.