The surface strain on a rubbing rubber surface was examined in the course of pattern abrasion. Rubbing experiments between the outermost surface of a rotating isoprene rubber wheel and a cylindrical lens were conducted. Observations of the contact area were made through the lens. Markers were put on the rubbing rubber surface to measure strain. The maximum strains at the inclined rubber surface between the ridges were from around 40% to 100%. In order to measure the strain at the crack‐propagating area, a marker was put on the lower front part of the ridge. It was found that the strain necessary for crack propagation underneath the ridge was 750%, which was almost equivalent to its breaking strain, irrespective of the applied load. At that moment, newly generated crack surface was confirmed. However, no visible crack was observed through an optical microscope when the strain was measure at 200% to 400%.