In this study, a survey of the thermal environment has been carried out to determine the thermal effects of the park and inner river on the urban environment in Koto-ku, Tokyo. The main results can be concluded as follows, 1) the air temperature near the inner river and park has shown a lower value than that in the street by 1-2℃. 2) It has been found that the farther the survey point is from the river, the higher air temperature becomes. 3) Under the same radiation, the surface temperature in the urban surfaces mainly affected by the type of the surface materials. In spite of the characteristics of the urban space, the concrete surface temperatures have the same change during the day. 4) By the regression analysis, it has been validated again that air temperature has close elation with the surface temperature in the urban space. 5) There are tendency that the air temperature becomes much higher with the increase of the plot ratio of the building block. 6) The valuation of the cooling effect of the urban structure on the thermal environment has found that the park and inner river has a lower radiate heat release into air than the concrete space
