Tokyo is one of the largest cities in the world and has a population of 20 million within its metropolitan area. A short history of air quality in Tokyo and its surroundings is summarized in this paper. Urbanization and industrialization have induced a drastic change in air quality and urban climate in Tokyo during the past forty years. Heat island in the urban area is thought to be a good symbol of man-made climate. In accordance, the change of temperature distribution for every five years and also how temperature distribution is affected by air is mentioned.