In the present study, we investigated the effects and regulatory mechanism of exosomal miR-221-3p derived from BMSCs on TGF-β1-induced proliferation, migration, and ECM deposition in ASMCs, and then verified its effect on asthma progression in ovalbumin (OVA)-induced asthmatic mice, aiming to provide a novel therapeutic target for asthma. This evidence concerns the gene TGFB1 and asthma.