With the aim to explore the effects of AMPK activity, AMPK mRNA expression (PRKAA1, PRKAA2) in beef during the post-mortem period were measured in Yushu yak (4500m above sea level), Gannan yak (3000m above sea level) and Simmental hybrid beef (1500m above sea level) changes in glycolysis and energy metabolism. The results showed that the AMPK activities was in a ascending trend as Simmental hybrids, Gannan yak and Yushu yak;the expression of PRKAA1 in Simmental hybrid was slightly lower than that in Gannan and Yushu;the expression of PRKAA2 in Simmental hybrid was significantly lower than that in Gannan and Yushu (P<0.05). In 12~168h, lactate content and free glucose content were in a ascending trend as Simmental hybrid cattle, Gannan yak and Yushu yak;in 72~168h, pH value and muscle glycogen content were in a descending trend as Simmental hybrid cattle, Gannan yak and Yushu yak;early maturity ATP, ADP and AMP were in a descending trend as Simmental hybrid cattle, Gannan yak and Yushu yak. In summary, as PRKAA1 and PRKAA2 gene expression in high-altitude beef body was high, AMPK was activated to increase activity, ATP concentration was lower, AMP production was increased, tissue glycolysis was accelerated, muscle lactate content was increase and pH value was lowered, thus affecting the quality of meat. The activity of AMPK in beef was increased under high altitude with hypoxia adaptability, which accelerated glycolysis metabolism and more effectively regulated energy generation.