Abstract: To investigate the effects of age on meat qualities and nutrition of Yunnan local steer,9 meat samples were taken from 9 steers,whose ages were 9 months,18 months and 30 months(3 steers per age group).Meat qualities and nutrition were measured. The results showed that shear force,a* and b* were significantly different(p<0.05) compared within the 3 groups,meanwhile,cooking loss,water loss,p H and L* had no notable differences. The shear force of group 9 months and 30 months were significantly higher than group 18 months,a* and b* of group 18 months and 30 months were significantly higher than group 9 months. L* showed no regularities,cooking loss and water loss showed no notable differences,but they showed down trend with the steers' aging. There were significant differences on water content,fat content and ash content(p<0.05). The water content of group 9 month was 75.84%,which was 4.37% higher than group 18 months and 7.64% higher than group 30 months. Fat content of group 18 months and 30 months were 4.11% and 7.50% higher than group 9 months. Ash contents of group 9 months and 18 months were the same,which was 0.12%(p <0.05)lower than group 30 months. Meat qualities and nutrition of Yunnan local steer were significantly influenced by ages,especially tender,color,water and fat content. This research provided a theoretical reference for further study on meat quality and nutrition of Yunnan local steer.