Objective To observe the effect of hypoxia reoxygenation on activity of superoxide dismutase(SOD)and MDA content as well as[Ca~(2+)],concentration and mitochondria membrane poten- tial of intestinal epithelial cell-6(IEC-6)in IEC culture medium and explore the protective effect and mechanism of serum containing Ziqi-liquid(a preparation of Chinese herbal medicine)on hypoxia reoxy- genation damaged IEC-6.Methods Hypoxia reoxygenation damage model of IEC-6 was made.SOD activity and MPA content in IEC-6 culture medium were determined by ultraviolet spectrometry after hy- poxia reoxygenation and treatment with Ziqi-liquid.Meanwhile,MMP changes and[Ca~(2+)]concentration were detected by laser scanning confocal microscopy.Results After hypoxia reoxygenation,SOD and MMP were significantly decreased,but MDA content and[ Ca~(2+)] concentration significantly increased (P＜0.01),and significantly facilitated by serum containing Ziqi-liquid.Conclusion Hypoxia reoxy- genation can damage IEC-6,but the serum containing Ziqi-liquid has significant protective effect on it.