To evaluate the effect of river and canal on thermal environment, we performed the field observation at the Tama River and the Shibuura Canal. The detailed measurement of vertical temperature distribution within the river and the canal and measurement of urban temperature along the street crossing the river and the canal were carried out and horizontal extent of cooling effect were confirmed by these observation. In the Tama River, the cooling effect is restricted in day time, while in the Shibuura Canal, this cooling effect appeared in night time
