BACKGROUND: Since the three-dimensional (3-D) structure of dermal tissue has an important role in regulating cell behavior and directing the wound healing process, the characteristic of the 3-D structure of dermal tissue needs to be clarified. OBJECTIVE: To explore the different 3-D structures between normal and scar dermal tissues. MATERIAL AND METHODS: Phase-contrast microtomography with synchrotron radiation technology was applied to detect the 3-D structure of dermal tissues. RESULTS: The normal dermal tissue consists of elliptical structures formed by fiber bundles interwoven in a helical manner. A regular louver-like structure was observed on the fibers. In scar tissue, the fiber bundles were arrayed in parallel, the louver-like structures were disordered. CONCLUSION: The study demonstrates the mesoscopic difference between normal dermal tissue and scar tissue, suggests that the high level of interweaving capability of collagen is compromised/lost when dermal tissue is injured, and provides a basis for future studies.