Abstract: 18 cases of adult patients with acute Lymphocytic leuaemia （ALL） were classified by theuse of monoclonal antibodies,among whom 13 were defined as common ALL;4 as Null ALL,and1 as T ALL.The mean duration of first complete remission （CR）attained was 39.4 dags in morethan half of the C-ALL,and while in CR sustained for 12.5 months.8 of the 13 C-ALL casesdied with a mean survival of 20.4 months.None of the 3 treated N-ALL patients attained CR,2of whom died with a survival of 1.8 and 11 months respectively.1 case of T-ALL survived for 1month.The results suggest that the immunologic subtying in adult ALL seems of value in evalu-ating the response to therapy and prognosis.