Wind-induced natural ventilation is essential for the refuge floor design of high rise buildings in Hong Kong. Cross ventilation is achieved by two sides of the refuge floor being open to the outside. The wind flow on the refuge floor will be influenced by the presence of a large service core. The Hong Kong open refuge floor concept occupying at least 50% of a floor is unique and is therefore vastly different from the limited refuge area proposed in the US during the 1980’s. This paper presents a computational fluid dynamic study of the refuge floor design in relation to wind-induced ventilation flow. The study also considers the effect of different wind angles when using square and circular shaped service cores on the refuge floor.