The blood sample of healthy and convalescents calves were analyzed the ABL-2analses instrument.They included pH、Po2、Pco2 HCO3- act·、HCO3- st·、BE· Using T-test for the rate of these determinations The two groups had obviously difference in pH、Pco2、HCO3- act· and HCO3-/Pco2(P<0 01).But Po2、HCO3- st· and BE had no difference in two groups.