Abstract: AIM One center experience is presented of the safety and feasibility of implanting the WATCHMAN left atrial appendage closure device at the ostium of the left atrial appendage to prevent thrombosis embolism in patients with atrial fibrillation (AF) in China. METHODS Nonvalvular AF patients between 40 and 90 years of age whose CHADS2-VAS score was≥2 and HAS-BLED score was≥3 were selected. Patients did not want to take long-term oral anticoagulant drugs or had contraindications for the use of oral anticoagulant drugs. The WATCHMAN left atrial appendage closure device delivery system was implanted into the ostium of the left atrial appendage. RESULTSThere were 102 AF patients enrolled with an average age of (72±9) years, average CHADS2-VAS score (5.3±1.2) and HAS-BLED score (3.45±0.6). Average procedural time was (76±18) min. All patients were successfully implanted with the WATCHMAN left atrial appendage closure device. Peri-procedure and after 2 months follow-up, no complications such as bleeding and embolism were found. CONCLUSION We demonstrated the safety and feasibility of implantation of the WATCHMAN left atrial appendage closure device at the ostium of the left atrial appendage to prevent thrombosis embolism in Chinese AF patients.