Two type degeneration processes: dehydration and proteolysis are studied, and the description based on polarization sensitive optical coherence tomograph (PS-OCT) measurement is presented respectively. Birefringent changes due to dehydration or proteolysis process are different. For the former case, the average birefringence increases with dehydration, caused by the size and index changes of muscle fibers. However, the hydrolysis process shows an opposite tendency. The average birefringence decreases with proteolysis, which can be explained by the damage of fibrous microstructures and the appearance of isotropic scattering elements. The above experimental results reveal different optical and microstructural changes in these two degeneration processes, and can be used to evaluate the muscle quality.