Histological analysis is widely used to evaluate injured tendons; however, it has the limitation of being semi‐quantitative. Hence, a quantification method to objectively evaluate the fibrous structure of tendons was developed with exhibiting the optical property of birefringence by using polarization‐sensitive optical coherence tomography (PS‐OCT). The phase retardation images was quantified according to the degree of repetition of the period. The obtained frequency value of the peak from the Fourier transform of the periodic pattern in the phase retardation image indicates the degree of the structural arrangement of collagen fibers. The better the arrangement of the collagen fibers results the higher the frequency values, and a disordered collagen fiber architecture results in a lower repetition frequency value. The scoring method well represented the fibrous structural changes of the injured Achilles tendon according to the wound healing state with a partial‐rupture rat model. Further details can be found in the article by Yong‐Jae Lee, Eunwoo Park, Kwan Seob Park, Jun‐Hyuk Lim, Sungmin Kim, Myung‐Sun Kim, and Tae Joong Eom (e202200065).image