The tactile-force function is high important on development of humanoid robot and human interface because it leads to the improvement of safety and operability. Human tactile mechanism is due to the tactile receptors. For the reason that it is possible to regard the tactile receptors as a mechanical sensor, those researches focused on the tactile receptors are being performed them. Thus, we have developed flexible tactile sensor that silicone rubber embedded in diaphragm strain gauges with the aim to detective a wide range of distortion and a small number of channels. Diaphragm strain gauge is the strain gauge which resistance element is disposed on the circumference. This is suitable for the detection of the wide range of distortion because the axial direction of the distortion is not limited. We performs a load test to verify the detection of distortion quantitative corresponding to the load, hardness tests using three different hardness materials, and examined the efficacy of the sensor developed.