ObjectiveTo investigate plasma pro-and anti-coagulation factor activity of patients in the perioperative period of surgical correction for tetralogy of Fallot (TOF) and its clinical significance. MethodsFrom January 2010 to April 2013, 47 patients undergoing surgical correction for TOF in Southern Hospital of Southern Medical University were enrolled in this study. There were 35 male and 12 female patients with their age of 1.20-26.00 (8.00±6.48) years and body weight of 8.70-46.00 (18.20±21.50) kg. Preoperatively and on the 4th, 7th and 10th postoperative day, activity of plasma coagulation factor Ⅱ, Ⅶ, Ⅷ, Ⅸ and Ⅹ, and antithrombin Ⅲ (ATⅢ) and protein C levels of all the patients were routinely measured, as well as prothrombin time (PT) and activated partial thromboplastin time (APTT). ResultsActivity of plasma coagulation factor Ⅱ (on the 4th postoperative day:102.66%±20.61% vs. 69.27%±16.51%), Ⅶ, Ⅷ, Ⅸ and Ⅹ(on the 4th postoperative day:125.43%±39.97% vs. 64.80%±11.46%) of TOF patients in the early postoperative period was significantly higher than preoperative level, reached the summit between the 4th and 7th postoperative day, and was still significantly higher than preoperative level on the 10th postoperative day. PT and APTT levels significantly decreased in the early postoperative period, and were still significantly lower than preoperative levels on the 10th postoperative day. Plasma AT Ⅲ and protein C levels were significantly increased in the early postoperative period but returned to preoperative levels on the 10th postoperative day. ConclusionsPreoperatively, haemostatic function of TOF patients is usually abnormal. Postoperative increased plasma procoagulant factor activity and recovered haemostatic function may be related to the correction of hypoxic state. In the early postoperative period, increased plasma procoagulant factor activity is helpful for haemostatic function. In the late postoperative period, an imbalance of provs anti-coagulation factors in plasma occurs towards stronger haemostatic function, which may increase the risk of thrombosis and render anticoagulant and antiplatelet therapy necessary.