Objective   To study changes of cardiac muscle enzyme in newborn infants with asphyxia  Methods   AST, LDH, CPK and CK、MB were assessed in 134 newborn infants with asphyxia and 30 healthy volunteers as controls.Results   The AST, LDH, CPK and CK、MB increased in the newborn infants with asphyxia in comparing to the normal group,which was proportional to the severity of asphyxia. Conclusion  The changes in cardiac muscle enzyme are early,sensitive and specific indexes for diagnosing asphyxia in perinatal period.