The measurement of perceptual sensitivity can be used for the clinical diagnosis and assessment of skin conditions. However, conventional approaches to evaluating the direct relationship between perceptual sensitivity and the skin mechanical properties have limitations. This study proposed a new approach to achieving the simultaneous measurement of skin deformation and perceptual sensitivity. We introduced suction stimulation on the skin, which is commonly used for evaluating the skin mechanical properties. However, the standard suction stimuli cannot produce sufficient stimuli to be perceived. We solved this issue by applying oscillated suction pressure in the frequency of 10 Hz. We presented the device mechanism and control method of the pressure. As a pilot study, we investigated the relationship between the deformation of the forearm skin and perceptual sensitivity in thirteen participants. Experimental results suggested that the amount of skin displacement achieves better discrimination performance than the suction pressure levels.