Ice friction is affected by various parameters such as temperature, humidity, and physicochemical properties of a substrate. One of the ways to reduce or increase ice friction is to curve patterns at the bottom of a substrate. To investigate the effect of the patterns, we tested a single PDMS pattern with quartz prism to visualize the real contact area. Friction force was measured by the rotational tribometer which operates at a wide range of velocity (0.03 to 10 m/s) and temperature (-10 to -1˚C). The real contact area was also measured to correlate with friction coefficient. We show that a pattern of a substrate reform the real contact area of friction. This result provides a theoretical basis of controlling friction by patterns of substrate.