PURPOSE To sutdy the effects of dibutyl pathalate (DBP) on the proliferation and apoptosis of leukemic cells from patients suffering from acute leukemia. METHODS The cell culture in vitro was used to study the effect of DBP on the proliferation of leukemic cells, while agrose gel electrophoresis of DNA fragments was used to study the effect of DBP on apoptosis of leukemic cells. RESULTS DBP could inhibit the proliferation of leukemic cells got from patients suffering from acute leukemia in vitro. The percentage of inhibition were 24.24% and 36.33% respectively when leukemic cells were exposed to 50?g/ml and 200?g/ml DBP for 24 hours. Leukemic cells from acute myelogenous leukemia were more susceptive to DBP than those from acute lymphocytic leukemia. DBP also induced the leukemic cells from patients to die via apoptosis and showed typical "ladder" of DNA fragments for apoptotic cells in agrose gel electrophoresis. CONCLUSION DBP could clear the leukemic cells in bone marrows of patients suffering from acute leukemia by suppressing the growth of leukemic cells and inducing them to die via apoptosis.