The purpose of this study was to draw optimal cases of the Urban Greening Type helping to mitigate the Urban Thermal Environment in Summer. 960 cases were simulated from combinations with various building sizes (Building Coverage Ratio: 10, 20, 30%, Building Stories: 1~20F) and the type of Planting (Roof, Wall, Land: 0, 20, 40, 60, 80, 100%) with the Urban Climate Simulation System. The results of this studying are as follows. 1) It showed that the case of Land Planting carried has the lower temperature than Roof and Wall Planting about $-3^{circ}C$ in daily minimum temperature and $-2^{circ}C$ in daily maximum temperature 2) Tree Evaporation from Land Planting has a great influence on temperature decrease in Urban Thermal Environment 3) As a result of the Average Temperature in day and night time, Land Planting has the lower temperature than Roof and Wall Planting, which implies that it can be a effective method to mitigate the Urban Tropical Night Phenomenon in Summer. In this study, it appears that the Land Planting can be the most effective method to help the mitigation of the Urban Thermal Environment in Summer and it is identified that the combination of Building Size and Planting can change climate and Heat Load from Building in the Urban Area.