Objective To explore the effect of serum deprivation on proliferation and apoptosis of cardiomyocytes and its mechanisms. Methods Human cardiomyocytes AC16 were randomly divided into serum-deprivation group (the cells were cultured in DMEM medium without fetal bovine serum for 48 h) and control group (the cells were cultured in DMEM medium containing 10% fetal bovine serum for 48 h). CCK-8 assay was performed to test the proliferation ability, and EdU imaging was conducted to detect the DNA synthesis level. Flow cytometry was performed to analyze the apoptosis level and mitochondrial membrane potential. Western blotting was conducted to detect the protein expression levels of caspase-9, Bcl-2, P53, proliferating cell nuclear antigen (PCNA), cyclin D1, β-catenin, Wnt5a, Axis inhibition protein 1 (Axin1), dishevelled 2 (Dvl2), dishevelled 3 (Dvl3) and low-density lipoprotein receptor-related protein 6 (LRP6). Results CCK-8 assay showed that the optical density value of the control group was 1.93±0.01 and that of the serum-deprivation group was 1.08±0.08, which was 55.8% of the control group, and there was significant difference between the two groups (P<0.01). DNA synthesis was inhibited by serum deprivation, and the DNA synthesis level of the serum-deprivation group was 65.6% of the control group, with significant difference found between the two groups (P<0.05). Serum deprivation could induce cardiomyocyte apoptosis; the apoptotic rate of control group was (6.34±0.47)%, and that of serum-deprivation group was (56.83±1.90)%, which was 8.9 times of the control group, and there was significant difference between the two groups (P<0.05). Serum deprivation could decrease the mitochondrial membrane potential of cardiomyocytes, while there was no significant difference between the serum-deprivation and control groups (P>0.05). Western blotting analysis showed that serum deprivation could upregulate the protein expression of caspase-9 and downregulate the protein expression of Bcl-2, P53, PCNA and cyclin D1. Serum deprivation could inhibit the protein expression of β-catenin, Wnt5a, Axin1, Dvl2, Dvl3 and LRP6 in cardiomyocytes. Conclusion Serum deprivation can inhibit proliferation and induce apoptosis of cardiomyocytes, which may be mediated by inhibition of Wnt/β-catenin signaling pathway.