Abstract: Objective To investigate the effects of simulated microgravity on autophagy of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). Methods Human induced pluripotent stem cells (hiPSCs) were cultured and differentiated into cardiomyocytes chemically in vitro.The hiPSC-CMs were randomly divided into two groups,simulated microgravity for 72 h (MG group) and stationary control (CON group).The subcellular structures were observed by transmission electron microscope,and the autophagy expression levels of LC3 and Atg 7 were detected by Western blot assay. Results Compared with the control group,simulated microgravity significantly increased the formation of autophagy and autolysosome (P<0.05),and enhanced the protein expression of LC3-Ⅱ/LC3-Ⅰ and Atg7 in hiPSC-CMs (P<0.05). Conclusion The autophagy is activated in hiPSC-CMs post simulated microgravity which might participate into the cardiomyocytes program death.