To explore the adaptive mechanism to hypoxia in Tibetan Antelope (Pantholops hodgsonii), we compared the contents of myoglobin (Mb), lactic acid (LD) and the activity of lactate dehydrogenase (LDH) in cardiac and skeletal muscles by spectrophotometry in Tibetan Antelope and Tibetan Sheep from the same elevation . The results showed that the contents of Mb in cardiac and skeletal muscles of Tibetan Antelope were significantly higher than in Tibetan Sheep (P<0.05), while no significant difference was observed between cardiac and skeletal muscles in Tibetan Antelope (P>0.05). However, the content of Mb in cardiac was significantly higher than that in skeletal muscle in Tibetan Sheep (P<0.05). The contents of LD and the activity of LDH in cardiac and skeletal muscles of Tibetan Antelope were significantly lower than in Tibetan Sheep (P<0.05), and the activity of LDH in cardiac muscle was significantly lower than that in skeletal muscle in the two groups. The results suggest that Tibetan Antelope could improve its ability to obtain and store oxygen under hypoxia by increasing the contents of Mb in cardiac and skeletal muscles,so that its cardiac and skeletal muscles could be supplied with rich oxygen in hypoxic environment. On the contrary, Tibetan Sheep is also a hypoxia-adapted species; it has less Mb, but higher LD content and LDH activity in cardiac and skeletal muscles, suggesting that it may obtain most energy from aerobic oxidation. Therefore, we speculate the above-mentioned differences might be related to different sports capabilities of two hypoxia-adapted species, and we consider that higher Mb content in Tibetan Antelope might be one of the molecular mechanisms for hypoxia adaption.