A large amount of research has been published in Taiwan on the reduction of the urban temperature for different strategies. The most important strategy for reducing ambient temperature is increasing green roofs or green spaces in city. For analyzing the effect of the vegetation on the thermal environment, this paper collects temperature and humidity data from two building roofs, one park and two streets which are located within same area and tries to analyze the thermal influence of vegetation in study area. The result of this research shows that the maximum cool effect of green roof was -1.60 °C and the maximum temperature difference between park and street was -2.00 °C. Therefore, it can also provide useful data to governments for calculating the environmental benefit if they carry out a green space and green roof policy.