This paper presents a novel haptic mouse that can be used as a human-computer interface and offers the capability of displaying properties such as patterns, gratings, and roughness. A small planar-distributed pin array is developed. Since the tactile display unit is small enough to be embedded into a computer mouse, we developed a texture display mouse. The performance of its texture display capability was verified. In addition, two psychophysical experiments have been conducted in order to ascertain the influence of vibrotactile stimuli. The first experiment showed that vibrational stimuli could be effective in the perception of patterns while from the second experiment, the functional relation between perceived roughness and component of vibrotactile stimuli was obtained. The experimental results have been applied to the development of a test-bed program.