Abstract: In order to establish and perfect the objective evaluation system of frozen lamb, in this research, the effects of frozen temperatures including-30, -40, -50, -60, -70 ℃ on the quality of Tan mutton were investigated, and the p H and juice loss rate were measured, the quality evaluation model of mutton was constructed by principal component analysis.The results showed that different freezing temperatures had no significant effect on the cooking loss ( p > 0.05) , with the increase of freezing temperature, the p H decreased ( p < 0.05) , the hydraulic fluctuation decreased, the juice loss rate increased, the brightness and redness value decreased, and the shear force value fluctuation decreased. The first to the second principal component of the cumulative contribution rate reached 95.74%, enough to describe the seven physical and chemical indicators reflect the quality of Tan mutton.Meanwhile, the model had a good agreement with sensory evaluation, it can synthetically reflected the quality, provide a new evaluation method of mutton physical and chemical quality.