Wide angle X-ray diffraction (WAXD) mapping analysis around the crack tip of natural rubber filled with carbon black was carried out using an X-ray beam with 3 micro meter width to identify the strain-crystallized area. In the filled sample, crystallized area was found to be wider than the case of unfilled sample, even though the macroscopic draw ratio was the same. The preferential crystallization in the filled sample was explained by the enhanced draw ratio of the deformable rubber component, since carbon black and its surroundings are not deformed. A new technique that uses an attenuator in place of the beam stopper was developed to detect the beam intensity after passing through the sample. This new technique is useful when an ion chamber cannot be arranged between the sample and the detector for the detection of the beam intensity. By the new technique, enhanced local deformation around the crack tip was clarified.