Aim To investigate the changes of endothelin (ET),calcitonin gene related peptide (CGRP), angiotensin Ⅱ (AngⅡ) and atrial natriuretic polypeptide (ANP) in plasma of patients underwent coronary artery bypass graft (CABG). Methords ET, CGRP, Ang Ⅱ and ANP in plasma of 32 patients with coronary heart disease who had the CABG operation were studied. The pericardium, auricle, pericardial fluid were got during the CABG operation. The tissue were homogenated, centrifuged and the supernatant was got; anticoagulant blood were centrifuged and the plasma was got then the ET, AngII, CGRP and ANP in the luquid were assayed by RIA. Results ET in the pericardial and auricle were very different (p<0.001). AngⅡ in the plasma and pericardial fluid were obviously different, and the same as that in the pericardium and auricle (p<0.001). CGRP in the plasma and pericardial fluid, pericardium and auricle, were also different (p<0.05,p<0.001). Though there was no difference of ANF between plasma and pericardial fluid, ANF in the pericardium was higher than in the auricle (p<0.001). Conclusion Different tissue of CABG patients had alternated ET,CGRP,AngⅡ and ANP.