Abstract: objective To determine the proliferative activity of HL60 cells affected by chondroitin sulfate (ChS), to inquire the ChS's application value in chemotherapy of malignant tumor. methods The proliferative activity was measured using cell count after added ChS with different concentration. Add ADR to each group of ChS with different concentration , compare the different surviving rate of cell with other groups.The acid phosphatase activity of each group was examined with ELISA in order to observe the differentiation of HL-60 cell. results The concentration of ChS(<50mg/l) can increase the cell density of HL60 obviously (P<0.01), but the density of cell showed a little difference when the concentration increased above 50 mg/l (P>0.05). After ADR had been added, the cell's surviving rate of each ChS group showed a decrease in different degree, especially the ChS concentration above 25 mg/l (P<0.01).The acid phosphatase activity of each group increased very obviously,especially in 75mg/l group. conclusion ChS with a proper concentration can accelerate the proliferative activity of HL60 cells; And it can increase the sensibility of HL60 cell which added ADR and increase the killing effect of ADR obviously to HL60 cell.