Abstract: Three alkaloids: harringtonine, cephalotaxine and schelhammera alkaloid B were isolated from Cephalotaxus oliveri Mast. which is distributed in Guangdong Sheng. The inhibiting effect of harringtonine for sarcoma 180 in mice was 42.3% at a dosage of 1 mg/kg. It showed high activity against the acute nonlymphoblastic leukemia in clinical experiments. A pretty high yield of 1.3/10000 antileukemic ingredient harring- tonine was extracted from the plant and the resources of C. oliveri Mast. in China are abundant, so that this plant is a good material to produce harringtonine.