To study the effect of co-culture of stromal cells and acute myeloid leukemia(AML) cells on drug resistance of AML cells and its mechanism.Stromal cells were co-cultured with acute myeloid leukemia cell HL-60 and then were treated with DNR, HHT and Ara-C for observing the sensitivity of HL-60 cells to drugs after incubation with HS-5. At the same time, the the inhibitor LY294002 of PI3K/AKT signaling pathway was used to treat the cells, so as to explore whether the changes of HL-60 sensitivity is associated with the activation of PI3K/AKT signal pathway after co-culture of cells.The statistical results of HL-60 cell inhibition rate showed that the HL-60 cell sensitivity to drugs was decreased after incubation with HS-5, the mRNA quantitation and immunblot detection showed that PI3K/AKT signaling pathway was activated after co-culture of HL-60 cells with HS-5 cells, in addition the CCND1, FOXO1, PTEN and other important genes were also changed significantly.After co-culture of HL-60 cells with HS-5, some important molecules of PI3K/AKT signal pathway are changed, such as CCND1,FOXO1, PTEN, finally leading to the change of HL-60 cell sensitivity to drugs.