ObjectiveTo evaluate the performance and safety of a novel device for left atrial appengdage (LAA) closure in dogs. MethodsThrough the fourth left intercostal, the LAA clips were implanted at the base of LAA in six dogs. Macroscopic pathology, histopathology and biological detection were performed at 7 d, 60 d, 90 d, 180 d after implan-tation respectively. ResultsThe devices were all successfully implanted at the base of LAA. There is no transposition of the LAA clips. Complete fibrosis and atrophy of LAA occurred at 60 d after implantation. LAA closure was completed with a new endothelial tissue layer developed on the occluded orifice of the left atrium after 60 d after implantation. The level of atrial natriuretic peptide did not decrease significantly after the device implantation (275.64±60.00 pg/ml vs. 248.34±56.10 pg/ml, P=0.529). ConclusionThe novel device for LAA closure achieved easy, reliable and safe closure of the LAA in canine model.