In this study, we provided citizens with environmental information by using animated three dimensional computer graphics (3DCG) to realize citizens the relationship between their behavioral activities and the amount of carbon dioxide reduction. In addition, it is possible to develop the actual city and the future city in 3DCG. So we developed an environment-friendly virtual city by using 3DCG. The purpose of this study is to analyze the effects of the environmental information using 3DCG on citizens' behaviors. In specific, the following two questionnaire surveys were conducted. The survey focused on citizen's environmental consciousness using three kinds of information tools. These tools are text-based information, still photo information and 3DCG information. The survey examined the effects of providing environmental information using 3DCG on the changes of citizen's attitude on environmental issues. According to the results of the questionnaire surveys, environmental information using 3DCG is found to be more effective in showing the relationship between their behavioral activities and the amount of carbon dioxide reduction than other information tools. Therefore, 3DCG is effective as a tool to draw attention to citizen's environmental consciousness.