This paper presents the processing technique of hidden hypersurface removal for 4-D space visualization. When 4-D space and objects are visualized in 3-D space by perspective projection, if a 4-D scene includes multiple 4-D objects and intricate structures, visibility becomes a fundamental problem in 4-D space visualization. To address this problem and improve the perception of 4-D space, we extend Warnock's area-subdivision algorithm, which is used for hidden surface removal in the domain of 2-D projections of a 3-D scene, to the domain of 3-D projections of a 4-D scene. The visualization results show that our algorithm can display a 4-D scene with correct visibility, and suggest that the hidden hypersurface removal can help us understand the spatial relationship of the 4-D scene.