Abstract: AIM: To study the dose-effects relationship of lipopolysacchride (LPS), phorbol 12-myristate, 13-acetate(PMA）, N-formyl-Met-Leu-Phe (fMLP）and calcium ionophore A₂₃₁₈₇ (A₂₃₁₈₇） on the production of intrerleukin-8 (IL-8) in cultured HL-60 cells and effects of different densities of HL-60 cells on the production of IL-8 induced by LPS. To observe the effects of several anti-inflammatory drugs, such as aspirin (Asp), indomethacin (Indo), salisylic acid (Sali), meloxicam (Melo) and hydrocortisone (Hcort) on the production of IL-8 induced by LPS in HL-60 cells. METHODS: The HL-60 cells were adjusted to appropriate densities and added to tissue culture plates, then stimulants or vehicle or drugs were added. The plates were incubated at 37℃, 5%　CO₂ for 24 h, then the supernatants were collected. The concentration of IL-8 in supernatants were measured by ELISA method with the limit of detection at 1.56 pg.mL^-1. RESULTS: All of the four stimulants—LPS, fMLP, PMA and A₂₃₁₈₇ were shown to enhance the secretion of IL-8 in cultured HL-60 cells. Asp, Sali and Hcort at the concentration of 1×10^-5 mol.L^-1 significantly inhibited IL-8 secretion stimulated by LPS 5　μg.mL^-1 for 24 h in HL-60 cells with the inhibition ratio of 86.2, 82.77 and 136.3%, respectively. It was also inhibited by isorhapotigenin at the concentrations from 1×10^-6 to 1×10^-4 mol.L-1, with IC₅₀ 2.23×10^-8 mol.L^-1. CONCLUSION: An easy and trustworthy method of assay for the production of IL-8 in HL-60 cells was established, which can be used as a model of selecting inhibitors of IL-8 production.