Abstract: Objective :To study the effect of SDF-1 in proliferation of acute myeloeytic leukemia cells HL-60,the correlated index was analyzed when SDF-1 activity was blocked by anti-CXCR₄ monoclonal antibody 12G5. Methods :HL-60 cells were cultured and co-cultured with normal stromal cells.24h after incubation with 12G5 (10μg/ml),cell cycle and PCNA expressions were detected with flow cytometry and immunohistochemical technique,respectivly.By means of rypan blue exclusion,cell survival rates were observed and growth curve was protracted. Results :The results were as follows:l) cell cycle in two groups were:experiment group G₀/G_l (56.71±4.9)% ,S (32.42±4.1)%,G₂/M (10.87±5.2)%, control group G₀/G_l (43.63±2.2)%, S (45.86±3.7)%, G₂/M (10.51±2.6)%, t-test analysis showed that 12GS induced more cells entering G₀/G_l,phase.2) survival rates of HL-60 cells decreased markedly compared to control group,and cell proliferation slow down.3)immunohistoehemical technique shown: PCNA positive rates in experiment group and control group were (42.1土3.9)% and (67.4土8.5)% respectively,t-test analysis showed that 12GS down-regulated PCNA expressions. Conclusion :SDF-1 can keep survival and proliferation course of HL-60 cell at certain level.