In order to investigate the edible quality change and correlation of yak rumen smooth muscle under different age. Water content, water holding capacity, cooking loss, shear force, and texture of yak rumen smooth muscle from 1~6 years-old yaks were measured. The results showed that with the increase of age, water content, water holding capacity, cohesiveness, springiness, and gumminess of yak rumen smooth muscle significantly decreased (P＜0.05); cooking loss, shear force, hardness, and chewiness of yak rumen smooth muscle also significantly increased (P＜0.05). Correlation analysis indicated that there were significantly correlation of yak age with water content, water holding capacity, cooking loss, shear force, and texture (P＜0.01). In summary, the yak rumen smooth muscle edible quality decreased with the age increasing. Therefore yak rumen smooth muscle would have a suitable edible quality by slaughter at a right age.