Abstract: Objective To study the role of remifentanil in protecting L02 cells against anoxia/reoxygenation-induced injury. Methods Cultured L02 cells were divided into normal control group (group C), anoxia/reoxygenation group (group O) and remifentanil treatment group(group R).Group R was further divided into 7 subgroups according to the different remifentanil concentrations.L02 cells in group C were normally cultured.L02 cells in groups O and R were exposed to anoxia for 5 hours followed by normal culture for 12 hours.The cell viability was assayed by MTT colorimetry, the cell apoptosis was detected by flow cytometry, and the LDH release from cells was measured by colorimetry.The dynamic changes of intracellular calcium concentration were observed under laser confocal microscope. Results The viability of anoxia/reoxygenation-injured L02 cells increased and the apoptosis of anoxia/reoxygenationinjured L02 cells decreased after they were treated with 5-40 ng/ml reminfentanil (P< 0.05).The LDH release from cells decreased after they were treated with 5-30 ng/ml reminfentanil (P< 0.05).The elevation of intracellular calcium concentration in anoxia/reoxygenation-injured L02 cells was delayed after treatment with 40 ng/ml reminfentanil (P< 0.05). Conclusion Reminfentanil at the concentration of 5-40 ng/ml can protect L02 cells against anoxia/reoxygenation-induced injury by inhibiting cell apoptosis and relieving calcium overload.