Due to increased indoor lighting energy consumption, various studies for reducing its consumption are being carried out. Among various methods, the light-shelf can bring natural light into indoors, reducing the consumption of lighting energy during daytime. Its efficiency has been recognized so that it has been applied and used in various studies and fields. The performance of external light-shelf has been recognized, but it is limited for applying to highrise buildings where are affected by wind pressure. In this study, the external light-shelf applied with the perforated reflector which can be applied to highrise buildings is suggested. Keyword: light shelf, Punched reflector, Vent ration, performance evaluation