The global warming has become a grave concern for mankind. Necessity of energy conservation in our daily life is advocated and policies for saving energy have been discussed in relation to urban environmental management. Here, growing attention has been paid to our lifestyles. In addition, however, we must consider the large amount of energy that are consumed for the improvement of urban infrastructures. Most of it is used through the input of materials such as irons and cements for construction works. From this viewpoint, the present study aims to analyze the energy consumption pertinent to urban infrastructure provision. Firstly, a method for analyzing such energy consumption is developed on the basis of the input-output model. Input of energy for a unit production expressed in monetary terms is calculated by using national input-output tables available today. It is shown that the input energy has been decreased remarkably during the 1955-1989 period in Japan. Secondly, estimation is made on the total energy value of the existing stocks of various infrastructures in the country. Thus this study aims to conduct the quantification of the life cycle environmental impacts related to the provision of various urban infrastructures.