Abstract： Objective To analyze the manifestation, treatment，outcome and potentially predisposing risk factors of perioperative thromboembolism after cavo-pulmonary connection, and to assess the effects of our prophylactic antithrombotic strategy.?Methods?Clinical data of 264 cases of bidirectional Glenn and 224 cases of total cavopulmonary connection （TCPC） operations undertaken from September 2005 to December 2010 in Fu wai hospital were retrospectively analyzed. Perioperative thromboembolic complications occurred in 9 patients. 5 of them were after bidirectional Glenn, 4 were after TCPC. Most of the 9 patients had at least one thrombi-related risk factor. The routine prophylactic antithrombotic therapy after these operations were intravenous infusion of heparin 10 U/（kg·h） initially, followed with oral aspirin 1-3 mg/（kg·d）. Results Thromboembolic events occurred within 7 days after the operation in 6 cases, appeared 2 to 4 weeks after the surgery in 3 cases. All 9 patients received anticoagulation with heparin. One patient also undertook take-down operation. 3 （33%） patients died, accounting for 33% （1/3）, and 18% （2/11） of the early deaths after bidirectional Glenn and TCPC operations. Clinical symptoms improved or disappeared in the remaining 6 patients. Conclusion The mortality of perioperative thromboembolic complications after cavo-pulmonary connection is high, consisting of the important cause of early deaths after these procedures. Our prophylactic anticoagulation strategy proved to be effective, though some thrombi-relatedrisk factors still need to be avoided.