The concerns lie on how to understand the environmental governance. Specifically, it means to control environmental issues from the legal perspective. It is to say that it is important to know how environmental policies comply with environmental laws. Therefore, the basic principle of environmental governance is firstly to build legislatures regarding pollution on atmosphere, water, soil, as well as waste management, and legally handle the issues. In other word, the principle of environmental governance is how to implement the legal management. Thus, in this paper, firstly, the development of environmental policy and its legislation are introduced. Then, typical acts for each field of environmental law are raised. Later, cases on European Court of Justice and the court of first instance are analyzed. Next, legal structure on environment in Japan and its related cases are described. By analyzing legal structure on environmental between EU and Japan, their comparative analysis is conducted. The main characteristic of environmental law in EU is that the environmental right has been clearly stated as one of the basic rights for citizens in the EC Treaty, the basic law for the Europe, or European Constitution yet to be ratified. On the other hand, the word environment does not appear in Japan's Constitution. Moreover, the Japanese court does not recognize environmental right as a practical right. As for the environmental legislatures, they are enacted in broad field both EU and Japan. Yet there seem quite remarkable differences on their implementation. While there have been already various court cases dealt with environmental issues in Europe, environmental cases brought to courts are very rare in Japan. There is a time lag between environmental policies in EU and Japan, reason of which lies on differences in future vision towards Environment in EU and Japan, while EU wants to play a world's leadership in dealing with environmental leadership, when Japan in still very cautious on implementing the environmental legislature.