Abstract: In order to investigate the effects of oxidation on the muscle quality and structure of Dosidicus gigas,this paper used a hydroxyl radical oxidation system(H₂O₂ concentrations of 1,5,10,50 mmol/L)to simulate the oxidization in vitro of Dosidicus gigas muscles. The carbonyl content,ultraviolet(UV)absorption spectrum,muscle microstructure,myofibril fragmentation index,cooking loss,centrifugal loss,low-field nuclear magnetic resonance were measured to compare the effects of different concentrations of H₂O₂ on muscle quality and the structure of Dosidicus gigas. The results showed that the carbonyl content of Dosidicus gigas myofibrillar protein increased significantly with the increase of oxidative concentration. When the concentration of H₂O₂ reached 50 mmol/L,the carbonyl content increased by 53.59% compared with the control group(P<0.01). Some chromogenic amino acids decreased,resulting in a decrease in the absorption peak of the ultraviolet(UV)absorption spectrum of the protein. The degree of damage to the muscle microstructure increased,resulting in the muscle fiber spaces dilatation and loose structure;The fragmentation gradually occurred,the myofibril fragmentation index increased,the index of 50 mmol/L was about 1.5 times than that of the control group(0 mmol/L),and the muscle water hold capacity decreased. In summary,in the hydroxyl radical oxidation system,the higher the concentration of the oxidant,the higher the degree of oxidation,and the more severe the damage of the myofibrillar structure,the lower the water hold capacity.