Quantitive assessments of serum cTnl, CK-MB in 106 coronary bypass graft (CABG) patients at base line after anesthesia induction; at the end of operation, and at every 6 hours during the first 24h post-operation and then, on 2nd, 3rd, and 5th postoperative day. The serum cTnl and CK-MB significantly increased from the end of the surgery to 5th postoperative day with the peak value (50.82 ± 31.72 mg/ml and 70.78 ± 64 UI/ml, respectively) reached on average 8-10h after the aortic unclamping. The aortic cross-clamping time correlated slight positively to the pear of the serum cTnl and CK-MB on the first postoperative day. The finding showed that the postoperative increase of cTnl levels in the CAGB patients resulted from several factors. The most important contributing factor was the cross clamping time, other ones were the cardioplegia types