The purpose of this study is to evaluate numerically the imporovement of urban climate by urban greenery as conducting Urban Climate Simulation System with E-GIS database and weather data. Results of the simulation are as follows. 1)4cases are set to the new town in Hae Un Dae area, Busan. CASE01 is senario which has only natural greens without additional greenery regulation but CASE02 take additional greens according to the governing law. CASE03 has as much amount of greens as possible and CASE04 has greens more than CASE03 by converting urban structures to accept more greens. 2)The temperature of CASE03 is $0.3^{circ}C$ lower than CASE01 and CASE04 is $0.4^{circ}C$ lower than CASE01. It means that it is possible to reduce the urban temperature up to $0.4^{circ}C$ by converting urban structures. 3)The temperature of CASE02 is $0.2^{circ}C$ lower than CASE01. It means that greenery regulation whose object is ground is effective to reduce urban temperature. Because sensible heat from the ground account for 54% of total. 4)When the temperature of the ground is approximately $0.8^{circ}C$ lower, the temperature is approximately $0.2^{circ}C$ lower.