Abstract: In order to understand the meat quality rule of Maiwa yak aged 1.5-3.5 years old, 10, 8 and 8 Maiwa yaks aged 1.5, 2.5 and 3.5 years were slaughtered for meat quality determination, including pH value, color difference, cooked meat rate and shear force. The results showed that there were extremely significant differences between Maiwa yak meat at 1.5, 2.5 and 3.5 years old（P＜0.01） at pH_{1 h} and pH_{24 h}, but no significant differences in shear force and cooked meat rate（P＞0.05）. The brightness（L^*） value, hue angle（H） value, the redness（a^*） value, the yellowness（b^*） value and the color saturation（C） value of 3.5 years old Maiwa yak were significantly different from that of 1.5 or 2.5 years old Maiwa yak（P＜0.01）. The yellowness（b^*） value was extremely significantly different from that in 1.5 years old Maiwa yak（P＜0.01）, and significantly different from that of 2.5 years old Maiwa yak（P＜0.05）. The results indicated that the meat quality of Maiwa yak aged 1.5, 2.5 and 3.5 years was better, and its tenderness was lower and processing performance was good, among which the quality of Maiwa yak beef aged 3.5 years was the best.