Objective To analysis the effect of different age factor on the prognosis and efficacy of acute cerebral infraction in patients treated by intravenous thrombolytic therapy with alteplase.Methods Ninety-eight patients with cerebral infarction were divided into older group (n=52) and younger group(n=46).Patients in two groups were trea-ted by intravenous thrombolysis with 0.9 mg · kg-1 alteplase.After 1 and 21 d, the efficacy was observed and scored using national institute of health stroke scale( NIHSS).At the same time,the incidence of adverse drug reactions were observed, and prognosis evaluated using Modified Rankin scale ( mRS ) in 3 weeks.Results NIHSS scores were signifi-cantly lower in the both groups treated by alteplase than those before thera-py( P<0.05).In 1 and 21 d, NIHSS scores were lower in the younger groups than those in elderly group ( P<0.05 ).The incident of adverse drug reaction was lower in the younger groups than the elderly group ( P<0.05).It has shown that the prognosis was better in the younger group than the elderly group ( P<0.05 ) by comparing mRS score in 3 weeks.Conclusion All acute cerebral infraction patients received sig-nificant benefits from the intravenous thrombolytic therapy with alteplase.The younger group had more significant efficacy, less complications and better prognosis than those of elderly group.