Operation of esophageal cancer accompanies a big surgical stress and postoperative pulmonary complications such as respiratory failure are observed at high frequencies. On the other hand, when a big stress is added to a body, a state of hypercoagulation in which blood coagulation mechanism is abnormally enhanced appears and this state is closely related to organ failures but has many unknown points. So, we examined 39 patients given excision of esophageal cancer with respect to occurrence of postoperative respiratory failures, participation of coagulopathy in aggravation and their degrees before and after the operation to find out the relationship between postoperative respiratory failure and the state of hypercoagulation. We gave a diagnosis of respiratory failure to the patients whose respiratory index exceeded 1.5 on the day after operation but did not show atelectasis or hydrothorax. As a result, respiratory failures were observed in 7 out of 39 cases (17.9%). When a risk score (RS) of postoperative respiratory failure was determined using multivalent analysis (quantification type II) with preoperative factors such as age and function of heart, lung, liver, and kidney as well as preoperative blood coagulation factors, RS = 2.87 (antithrombin-III (AT-III) less than 75%) +1.89 (age over 70 years) +1.78 (respiratory index over 0.15) +1.44 (serum albumin less than 3.0 mg/dl) +1.28 (cardiac index less than 3.0 l/min/m2) was obtained and a drop in preoperative AT-III was considered a risk for occurrence of post operative respiratory failure. In contrast, referring changes in postoperative value of blood coagulation factors, a distinct rise in fibrinogen (FBG) appeared in early stage after operation in the respiratory failure group compared to the control group (p < 0.01). Moreover, recovery in AT-III of blood coagulation factors and in plasminogen and antiplasmin of fibrinolytic factors was delayed (p < 0.05) indicating promotion of postoperative hypercoagulation state and delay in recovery of coagulation-fibrinolysis factors. However, participation of platelet factors was absent.