Aim To investigate the effect of miR-200c-3p on apoptosis of cardiomyocytes with hypoxia/reoxygenation and its mechanism. Methods H9c2 cells hypoxia/reoxygenation (H/R)model was constructed by treatment in hypoxia/reoxygenation incubator for 12 hours. The expression levels of miR-200c-3p and X-linked inhibitor of apoptosis protein(XIAP) mRNA were detected by Real-time fluorescent quantitative reverse transcription polymerase chain reaction(qRT-PCR). H/R+anti-miR-NC group (transfected with anti-miR-NC), H/R+anti-miR-200c-3p group (transfected with anti-miR-200c-3p), H/R+pcDNA group (transfected with pcDNA), H/R+pcDNA-XIAP group (transfected with pcDNA-XIAP), H/R+anti-miR-200c-3p+si-NC group (co-transfected with anti-miR-200c-3p and si-NC), H/R+anti-miR-200c-3p+si-XIAP group (co-transfected with anti-miR-200c-3p and si-XIAP) were transfected into H9c2 cells by liposome method and subjected to hypoxia-reoxygenation treatment. Western blotting(western blot), methyl thiazolyl tetrazolium (MTT) and flow cytometry were used to detect the expression of XIAP, Cysteine aspartic protease(Caspase-3), cleaved Caspase-3,Bü cell lymphoma/leukemia-2 X protein(Bax) and B cell lymphoma/leukemia-2(Bcl-2), cell proliferation and apoptosis respectively. The dual luciferase reporter gene assay was used to detect the binding of miR-200c-3pto XIAP in cells. Results Hypoxia-reoxygenation H9c2 cells were successfully constructed. Compared with the control group, the expression of miR-200c-3p was up-regulated, and the expression of XIAP was down-regulated in H9c2 cells with H/R. The inhibition of miR-200c-3p and overexpression of XIAP inhibited cell apoptosis, down-regulation of cleaved Caspase-3, Bax, up-regulation of Bcl-2 in H/R H9c2 cells; miR-200c-3p inhibits the fluorescence activity of wild-type XIAP cells and negatively regulates the expression of XIAP; Knockdown XIAP could reverse the inhibition of miR-200c-3p on the apoptosis of H/R H9c2 cells. Conclusion miR-200c-3p can promote the apoptosis of cardiomyocytes with hypoxia-reoxygenation treatment, and its intracellular mechanism is related to the regulation of XIAP, which will provide a new target for the treatment of ischemic myocardial injury.