The earth scale change of climate has brought a new kind of natural disaster and the developed and complicated city system is holding a latent risk of expanding the damage artificially. Also people has been spoiling the health since the immense quantity of chemicals have been produced and already used in pursuit of convenience and various toxic substances have been produced unintentionally and accumulated in environment. Therefore, We need some countermeasures from the viewpoint to prevent the city environment form disaster and to manage environmental risks. So we will develop and improve a new risk management system and a disaster prevention system to preserve and create the city environment where people feel easy and sound in their life.