In order to determine the violation of right of light impact at adjacent residential area by high-rise building, analysis on the right of light for high-rise residential commercial complex building block at Gahngnam-ku, Seoul, Korea was carried out using Google Sketchup Pro. After the analysis th sunshine duration of B apartment decreased from 5 hours 16 minutes 3 hours 48 minutes by I hour 42 minutes after construction. It shows that the total sunshine duration is less than the Seoul City Government Standard which is more than 4 hours a day, or more than 2 consecutive hours. Lowering the heights of apartments by 54m would increase the total sunshine duration which would meet the Seoul City Government Standard by four hours seven minutes. Problems that rna lead to the violation on the right of light in the adjacent area should be discussed in advance and minimized by analyzing the right of light among buildings and structures which are scheduled to be constructed on the site during construction penni! process when high-rise building is proposed.