Abstract: Objective:To analyze the usefulness of thromboelastography (TEG) in the perioperative period of cardiothoracic surgery. Method:A total of 101 patients who received TEG measurement perioperatively were analyzed retrospectively. There were 14 patients who received both pre-and postoperative TEG measurement. Nine patients were monitored preoperatively only, and 78 patients monitored postoperatively only. Total 115 TEG tests (including 23 tests performed preoperatively and 92 tests taken postoperatively) were accomplished. All TEG results, routine haemostatic assays such as APTT,PT, Fg, and platelet count were recorded. The platelet inhibition rate induced by AA and ADP ways of the 71 CHD patients was detected with Platelet Mapping assay, and total 102 TEG tests (including 60 tests performed preoperatively and 42 tests taken postoperatively) were accomplished. Result:There were eight patients (34.8%) preoperatively with abnormal TEG results mainly because of low fibrinogen, and seventy-three patients (79.3%) suffered from abnormal TEG postoperatively, including low fibrinogen (50.0%), heparin residual (42.4%) and platelet dysfunction (32.6%). Platelet function was decreased postoperatively compare to baseline (P<0.05).Most excessive bleeding patients had moderate to severe abnormal TEG results who were getting better after appropriate treatment, five patients not improving underwent re -exploration for bleeding and surgical bleeding were confirmed. By Platelet Mapping assay,14.6% of CHD patients taken aspirin and 16.7% taken clopidogrel were identified ineffective. Comparison of platelet inhibition rate induced by AA between aspirin group and aspirin combined with clopidogrel group was not significant (P>0.05). Conclusion:TEG test may be helpful for monitoring perioperative coagulation status and diagnosing excessive bleeding in cardiothoracic surgery and TEG could also guide the anti-platelet individual therapy for CHD patients.