Abstract: Objective To study the effect of artesunate on the production of heat shock protein(HSP70)and the apoptosis of macrophage in RAW264.7 cells induced by high temperature and lipo polysaceharide(LPS)composite factors.Methods Macrophage cell line RAW264.7 in vitro was divided into 4 groups(blank control group,hightemperature and LPS composite group and artesunate(AR)group)and incubated for 24hrs at 40℃ with 95%O₂ and 5%CO₂.The expression of HSP70 mRNA and protein was detected by RT-PCR,and the rate of cells apoptosis was assessed by flow cytometer(FCM).Results The rate of HSP70 mRNA expression in blank group,high temperature and LPS composite group and AR group was 10%,23% and 54%,respectively,with significant differ ences between high temperature and LPS composite group and AR group(P<0.05).The expression of HSP70 protein showed a coincidence with HSP70 mRNA,in contrast,there was an opposite tendency between the rate of apoptosis cells and the expression of HSP70 mRNA.Conclusion Artesunate could induce HSP70 mRNA and protein expression and obviously reduce the rate of cells apoptosis,and it may be one of the important mechanisms for protective effects against injury.