Abstract: The myoglobin pure solution system was used as the research object,the effect of heat treatment at 60~80℃ on the structure of myoglobin were investigated by ultraviolet-visible absorption spectroscopy,fluorescence and circular dichroism(CD)spectra. The results showed that,the absorbance of the characteristic peaks of myoglobin decreased significantly(p<0.05),and the fluorescence intensity of the maximum emission peak of the fluorescence spectrum increased significantly,and the α-helix content in the secondary structure decreased significantly(p<0.05)when heated at 80℃. However,60,70℃ treatments had little effect on the secondary and tertiary structure of myoglobin. Myoglobin was resistant to heating up to 70℃. As the heating temperature raised from 60℃ to 80℃,the denaturate degree of myoglobin,the detachment degree of hemoglobin,the expansion degree of tertiary structure,and the disordering of secondary structure were all increasing,which indicated that heating temperature above 70℃ would affect the structure of myoglobin seriously.