The mechanism of postmortem physiology was studied by AMPK activity and glycolysis indexes from 6 and 18 months postmortem lamb.The results showed that the 18 months lamb had significant higher in AMPK activity(P<0.01),the muscle glycogen content,lactic acid content,pH decrease amplitude,hexokinase activity(P<0.01) and lactate dehydrogenase activity(P<0.05) than 6 months lamb.It was also found that difference of AMPK activity and glycolysis indexes among different parts muscle of the lamb and the parts with higher amount of exercise had higher AMPK activity and glycolysis.Therefore we concluded that the glycolysis speed had a positive correlation with AMPK activity.