Vegetation has various effects on urban thermal environment. A part of these effects, micro climate and thermal sensation around the vegetation, were investigated by field measurements and experiments. A field measurement was done in the courtyards of some elementary schools in Naha to reveal the difference of thermal sensation by the surrounding vegetation and buildings. Thermal sensation was surveyed by the direct hearing from the residents at some places in Naha. Some voting experiments of thermal sensation by fixed subjects were also done in the campus of University of the Ryukyus. The elementary schools located in urban areas are important factors not only for the playground of children but also valuable open space with vegetation in the built-up areas from the view point of thermal environment. The measurements of outdoor thermal environment in two elementary schools which were located in the built-up area of Naha city were carried out during a half of a day, from 12 to 12 that includes both the daytime and the nighttime. Four measurement points were set in each school, and four factors of thermal comfort, air temperature, humidity, globe temperature and air flow speed, were measured. The thermal sensation index was calculated from the measured data. The clear effects of vegetation on thermal sensation were served in the daytime. The direct hearings of thermal sensation were done in summer and in fall during two years. The hearing sites were a sunny place and a shaded place in a park in 1995, and a sunny place in the most densely built-up area and a shaded place in another park in Naha city in 1996. The questions were thermal sensation, comfort sensation and expected air temperature. Dry bulb and wet bulb temperature, globe temperature and air flow speed were measured at the same place and time. The strong correlation between the thermal sensation and the actual thermal condition could not found in these data. Many subjects replied "comfort" when they felt "hot" or "slightly hot". The expected air temperatures by many subjects are closer to the air temperature than to the thermal sensation index calculated from the measured data.The voting experiments on outdoor thermal comfort in a i-tropical zone were done in summer and in fall. The experiment sites were a sunny place and a shaded place in the campus. Total number of the subjects was 30, and all of them were students. 5 subjects were set into a group. One group was exposed in the sunny site, and at the same time, another group was exposed in the shaded site for 20 minutes. They exchanged their positions after 20 minutes. They answered their thermal sensation and comfort sensation at 0, 2, 5, 10 and 20 minutes past. Thermal environmental factors were also measured at these times. There is a difference between the thermal sensation when the subject moved from the sunny place to the shaded place and the reverse movement.