In order to explore the effects of different thawing methods on the oxidation of mutton lipid and protein, semimembranosus and longissimus dorsi muscle of Kazakh sheep were taken as the research objects to determine the oxidation indicators. Moreover, the protein degradation in different parts was observed by SDS-PAGE. The results showed that after refrigerated thawing, the peroxidation values of semimembranosus and longissimus dorsi muscle were 3.33mmol·kg-1 and 4.58mmol·kg-1, and the mass ratios of malondialdehyde were 0.16mg·100g-1 and 0.24mg·100g-1. The carbonyl molality were 3.59nmol·mg-1 and 4.62nmol·mg-1, and the sulfhydryl molality were 41.26nmol·mg-1 and 38.73nmol·mg-1. The mass of the hydrophobic bond were 64.72μg and 75.25μg. After static thawing, the peroxide values of the two muscles were 4.91mmol·kg-1 and 5.79mmol·kg-1, and the sulfhydryl molality were 38.40nmol·mg-1 and 33.40nmol·mg-1 . Total protein solubility were 184.50mg·g-1 and 171.90mg·g-1, and sarcoplasmic protein solubility were 69.07mg·g-1 and 60.77mg·g-1. The myogenic protein solubility were 115.43mg·g-1 and 111.13mg·g-1. After air thawing, the peroxide value of the two muscles were 7.00mmol·kg-1 and 7.71mmol·kg-1, and the mass ratio of malondialdehyde were 0.33mg·100g-1 and 0.44mg·100g-1. The carbonyl molality were 13.19nmol·mg-1 and 14.06nmol·mg-1. The sulfhydryl molality were 17.46nmol·mg-1 and 12.56nmol·mg-1, and the hydrophobic bond mass were 75.20μg and 82.47μg. The oxidation degrees of thawing methods in ascending order were refrigerated thawing, static thawing, ultrasonic thawing, microwave thawing and air thawing(P＜0.05). According to the results of SDS-PAGE, the protein of mutton had different degrees of degradation after freezing and thawing. Ultrasonic thawing had a greater impact on the degradation of longissimus dorsi protein. This study showed that the refrigerated thawing and static thawing induced to lower oxidation degrees and better quality of mutton, which were more suitable for thawing frozen mutton.