Abstract: The changes of color during cooling storage quality of thawing raw- eaten yellowfin tuna steaks in 0, 2, 4, 6℃ and 8℃ were studied. In the process of cooling storage, the relative content of met Mb and color difference were tested to evaluate the quality and achieve the law of quality change.The time of the relative content of met Mb reached 50% at 0, 2, 4, 6 and 8℃ was 40, 48, 24, 20 and 18 h, respectively.And the relative content of met Mb had a significant relation with sensory evaluation ( p < 0.01) . Change of color combined with T test showed that a * ( redness value) and ΔE ( color difference) had higher correlation degree with cooling temperature and time.The higher the temperature, the bigger change the color difference had.There was a significant color difference at 6℃and 8℃, but the color difference at 0℃ was bigger than 2℃.The dynamic model on the content of met Mb changing with time was built. The model was accord with the first kinetics equation. The influences of cooling storage temperature on reaction rate constant were described by Arrhenius equation, which had a higher fitting precision.