Studies on the light-shelf as a solution for the problem of lighting energy consumption increase in buildings have been carried out continuously, but there is lack of studies on light-shelf according to the form of space. The purpose of this study is to evaluate the performance of light-shelf in form of cover ceiling and draw the appropriate specifications. The result of this study is as follows. 1) When applying light-shelf to the curve ceiling with 3 m of spatial depth, there is no lighting performance improvement. 2) In case the light-shelf is installed, the average illumination of indoor space is lower in comparison to the case of non-installation of light-shelf. And, as the height of ceiling increases, the average illumination of indoor space becomes lower. 3) The uniformity ratio of illumination tends to increase the width and angle of light-shelf due to the diffusion of light. 4) In the viewpoint of improving the spatial depth satisfying the standard illumination and uniformity ratio of illumination according to the installation of light-shelf, it is considered that the light-shelf with the width 0.6m and angle over 20 is appropriate specifications for curve ceiling.