Background: Calcium deposition in vascular smooth muscle cells (VSMCs) can lead to the rigidity of the vasculature and an increase of risk in cardiac events. This study aimed to explore the role of exosomal microRNA-151-3p (miR-151-3p) in the regulation of VSMC calcification. Methods: A cellular calcification model was established using the mouse primary aortic VSMCs by β-glycerophosphate treatment. The calcium deposition was evaluated by Alizarin Red staining. The expression of miR-151-3p in exosomes was evaluated by qRT-PCR. The relationship between miR-151-3p and Atg5 was determined by bioinformatics analysis and dual-luciferase gene reporter assay. The exosome derived from mouse VSMCs transfected with miR-151-3p mimics/inhibitor were isolated and used to stimulate VSMCs. The expression of Atg5, α-SMA, OPN, Runx2 and BMP2 was evaluated by western blot. An animal model was established to investigate the role of miR-151-3p in exosomes.Results: MiR-151-3p was significantly upregulated in the exosomes of VSMCs treated with β-glycerophosphate. Exosomes derived from calcific VSMCs increased the calcium deposition of general VSMCs without any treatment. Exosomes derived from miR-151-3p mimics transfected VSMCs increased the expression of Runx2 and BMP2, while reduced the expression of α-SMA and OPN in general VSMCs. and exosomes derived from miR-151-3p inhibitor transfected VSMCs reversed these effects in vitro. Meanwhile, miR-151-3p served as a ceRNA of Atg5 by directly binding to the 3'UTR of Atg5. Moreover, the expression of α-SMA, OPN, Runx2 and BMP2 in vivo was consistent with the results in VSMCs in vitro.Conclusion: Our study revealed that miR-151-3p in VSMCs-derived exosomes might induce calcium deposition through regulating Atg5 expression, suggesting that miR-151-3p might be a potential biomarker for vascular calcification.