Technologies on energy saving and materials used in curtain walls have progressed with increase of high-rise and large buildings. However, there is little study to explain fire resistance performance of whole system of the curtain walls since the curtain walls are classified as non-structural members in Korean Building Codes. Aluminum has been widely used as frame materials in the curtain walls. Recently, use of steel as the curtain wall frame is increasing due to its higher strength and thermal resistance as compared with aluminum frame. In this study, fire tests on the basis of EN 13830 were performed with aluminum and steel curtain walls. From the tests, fire resistance integrity, thermal insulation, and radiation properties were evaluated for both systems and compared. The results showed that the fire resistance performance of steel curtain wall was higher than that of aluminum curtain wall, and the properties of glass and sealants were important factors in the fire resistance of the curtain walls.