Abstract: Objective To investigate the expression of IL-15 and its receptor in children acute leukemia,contribute to understand their function on acute leukemia. Methods Every group of acute lymphocytic leukemia(ALL),acute myeloid leukemia(ANLL) or non-leukemia group had 20 children who did not receive any treatment.The expression of the interleukin-15 receptor alpha,beta,gamma mRNA in bone marrow were examined by RT-PCR,and make an Semiquantitative analysis.The level of IL-15 in serum of every group by means of ELISA. Results 　The level of IL-15 in AL (ALL and ANLL) group, were significant was assayed in statistics ( P < 0. 05) with healthy children and non-leukemia group . The difference which the IL-15 level of ALL compared with ANLL or the level of healthy children compared with nonleukemia group is neglected in statistics ( P > 0. 05) . The expression of IL-15R alpha, beta, gamma mRNA in AL is significantly different than that of healthy and non-leukemia children. The difference which the IL-15 alpha, beta, gamma of ALL compared with ANLL or the level of healthy children compared with non-leukemia group is neglectable in statistics ( P > 0. 05) . Conclusion 　The IL-15 level of AL children is lower than cont rol group. And the expression that of IL-15Rα,β,γ subunit in bone marrow mononuclear cell of AL is smaller than those of non-leukemia group.