Aim To investigate the relationship between microRNA (miRNA) and autophagy in aged myocardial cells induced by D-galactose. Methods The D-galactose with 0, 4, 8, 16, 20 g/L was used to induce the rat myocardial cells to senescence respectively,and being stimulated 3,6, 9 days later, the aging level of H9c2 was detected by the beta-galactosidase staining； the formation of autophagosomes in aging rat cardiomyocytes induced by D-galactose was detected by electron microscope； the mRNA expression level of miRNA-30a, miRNA-126, miRNA-204 and protein expression level of LC3B II/LC3B I in aging rat cardiomyocytes and H9C2 cells was detected by quantitative real-time(qRT-PCR) and Western blot methods respectively. Results Compared with the control group, the cell staining was gradually deepened with the increase of drug concentration and the stimulation days, and when D-galactose concentration was 8 g/L for 9 days, cell staining was the most obvious； electron microscopy showed that the autophagy in aging cardiomyocytes induced by D-galactose was decreased； Western blot results showed that the level of LC3B II/LC3B I in aging cardiomyocytes was reduced； qRT-PCR results showed that in the aging cardiomyocytes group the expression levels of miRNA-30a and miRNA-126 were decreased and miRNA-204 was significantly increased. Conclusion In the process of the autophagy level decreasing in senescent cardiomyocytes induced by D-galactose, there exists a reducing in miRNA-30a, miRNA-126 expression level and an increasing in miRNA-204 expression level, the differential expression of miRNAs may be an important mechanism of autophagy in senescent cardiomyocytes.