Aromatic turmerone (ar-turmerone) has been reported to have a cytotoxic effect on L-1210 and HL-60 cells. In the present study, we investigated the anticancer responses and immune activities in implanted tumor cells. Our study found that ar-turmerone inhibited the increase in the number of white blood cells, which normally increase by the injection of lymphoblast cells, or P388D1, and ar-turmerone increased lymphocyte percentage compared to the control. Tumor inhibition rate in the ar-turmerone-treated group was 11.79%, and the apoptosis indexes of the control, ar-turmerone and Glivec groups were 4.22±1.02, 5.45±1.46 and 10.01±2.01, respectively, in which only the Glivec-treated group showed a significance. The positive rates of Bcl-2 and Bax proteins which were treated by ar-turmerone did not show marked differences compared to the control group, but the Bax protein in the Glivec-treated group increased compared to the control group. The density of caspase-1, -3, -6, -9, Bcl-2, Bax, p21 and p53 mRNA in the control, ar-turmerone and Glivec groups did not change considerably, but the Bax mRNA of the Glivec-treated group increased compared to the control group. The ar-turmerone-treated group increased T-lymphocyte and B-lymphocyte proliferation activities compared to the control group, which was more significant in T-lymphocyte than in B-lymphocyte proliferation activity. The interleukin-2 (IL2) production activity of the ar-turmerone group increased compared to the control group. These findings suggest that ar-turmerone does not have a chemotherapeutic effect on tumor incidence, but it has a repressive effect on P388D1 lymphocytic leukemia. Furthermore, this protective effect of ar-turmerone from P388D1 lymphocytic leukemia resulted from the increased activity of tumor immunogenicity through increased T-lymphokine production and increased percentage of lymphocytes.