This article provides an introductory description of the national income taxation in Japan of businesses conducted by corporate entities. Generally speaking, the Japanese taxes on corporate entities consist of both national and local taxes, and the tax base relates to an entity's income, scale of business operations, value of depreciable assets, etc., although the major features of these taxes are found in the corporate income tax under the national law. This article describes the basic structure of the corporate income tax in Japan, the entities subject to the tax, the tax base and the international aspects of the tax.