The petrological characteristics of the Wakurayama dacite, Matsue city, southwest Japan have been examined. The activity of the Wakurayama dacite is about 5 Ma ago. In this study, petrological details of Wakurayama dacite became clear. Wakurayama dacite can be classified into the three groups of lava bodies shown below by field survey, the color of the rock and mineral assemblage under the microscope. Wakurayama dacite might be able to basically divided into three groups which are Red, Olive and Gray groups by their rock color.