Based on modal analyses, microscopy, and X-ray and electron microprobe analyses, descriptions are made on the Hobenzan granitic complex and associated base-metal deposits, which are located in Yamaguchi Prefecture, southwest Japan. The granitic complex (91 Ma) can be classified into three zones; hornblende-biotite granodiorite, hornblende-biotite granite, and biotite granite. The ore deposits occur in the hornblende-biotite granodiorite and also in the marginal part of the complex. The characteristic ore minerals are as follows: chalcopyrite, arsenopyrite, scheelite, cobaltite, bismuthinite, native bismuth, galenobismutite, aikinite, cosalite, cannizarite, and matildite, with occasional appearance of tourmaline. It should be noted to the fact that arsenopyrite and cobaltite are abundant in the western part of that complex, while galena and sphalerite tend to increase towards its eastern part. The present study reveals that the Hobenzan granitic complex is characterized by the associated Cu-Bi-W-Co-As-S mineralization with abundant tourmaline, which is a rare type of mineralization in Japan.