Background: Recent studies show oxytocin (OT) has various effects on cellular behaviors. Mesenchymal stem cells (MSCs) are studied for cardiac repair, and we reported the effect of oxytocin on umbilical cord -MSCs (UCB-MSCs). Methods: UCB-MSCs were pretreated with OT (100 nM) and washed out. Boyden chamber assay and the phase retardation imaging technique were applied. For in vivo study, ischemia-reperfusion was induced in rats and MSCs were injected into infarcted myocardium. To examine the cardiogenic effect of oxytocin, UCB-MSC was cultured with OT. Results: OT-UCB-MSCs increase transwell migration. In addition, the phase retardation imaging vividly showed in real time the effect of oxytocin on the dynamically changing cytoskeletal structures with multiple focal adhesion points coordinating during migration. Knock-down of MMP-2 by siRNA reduced the OT-induced transmigration activity. In OT-UCB-MSCs injected rats, macrophage infiltration was reduced while connexin43 was increased in peri-infarc zone. The engraftment rate on the myocardium of OT-UCB-MSC Group was 1.4-fold higher than that of the UCB-MSC Group. The percentage of cardiac fibrosis to the left ventricle was 44.18.5% in PBS Group, 33.910.6% in UCB-MSC Group, and 10.76.5% in OT-UCB-MSC Group. The LVEDP (mmHg) was lower in UCB-MSC Group (10.3짹3.4) and OT-UCB-MSC Group (9.1짹2.3) than PBS Group (14.7짹3.1). Cardiac contractility of OT-UCB-MSC Group was greater than that of UCB-MSC Group. On the other hand, UCB-MSC cultured with oxytocin for 7 days showed an increased expression of connexin43 and troponin T. In addition, Glycogen synthase kinase-3棺(GSK3棺) and phosphorylated signal transducer and activator of transcription 3 (STAT3), which were known to regulate the fate of stem cells were translocated into nucleus. Conclustion: Transient stimulation of UCB-MSC with oxytocin enhances migration capacity, and prolonged treatment with oxytocin could induce to cardiogenic potentialized UCB-MSCs for cardiac repair.