Three hundred consecutive adult patients having cardioaortic surgery under the cardiopulmonary bypass for a variety of cardioaortic lesions were evaluated retrospectively for postoperative hyperbilirubinemia[above 5mg/100ml].We found twenty eight patients with postoperative hyperbilirubinemia and divided them into two groups according to the postoperative day of peak s-bilirubin .Group A was the patients with a peak s-bilirubin level within three days ,and group B above three days postoperatively.Group B was divided into group S[survive] and group D[death] . We had compaired the survival & death group and observed the correlation between the decreasing tendency of postoperative s-bilirubin & the nutrition per os in group B. The incidence of postoperative hyperbilirubinemia,as defined by a s-bilirubin concentration of 5.0mg/100ml or greater,was 9.3%.The mortality rates of group A & B were 0.0% and 35.7% respectively.Important contributing factors between group A & B were the age,duration of ICU,Max.DOAB[maximum dose of catecholamine used],amount of blood transfused during or shortly after surgery and preoperative pulmonary hypertension[main pulmonary artery pressure > 30mmHg] and backward heart failure. The risking factors of group D compared to group S were as follows the age,preoperative & postoperative SGOT[serum glutamic-oxaloacetic trasaminase],postoperative total & indirect bilirubin,cardiopulmonary bypass time,duration of ICU & mechanical ventilation ,Max.DOAB,preoperative pulmonary hypertension and backward heart failure.The six patients in group B showed good correlation between the decreasing point of s-bilirubin and the starting day of oral or tube feeding.