Abstract: OBJECTIVE To observe the effect of nicorandil on the hemodynamics and cTnⅠ in patients undergoing off-pump coronary artery bypass graft(OPCABG). METHODS Sixty scheducled patients were randomly divided into group control(Ⅰ), group nicorandil(Ⅱ, Ⅲ and Ⅳ). In group Ⅱ,10 mg nicorandil was oral administered before operation; whereas in group Ⅲ, the same dosage nicorandil was administered before operation, then 20 mg nicorandil was injected introvenously after induction of anesthesia; in group Ⅳ, 20 mg nicorandil was injected intravenously after operation. The concentration of cTnⅠ was determined at the following time points: after induction(T₀), the ending injecting of nicorandil or normal sailine(T₁), 1 h(T₂), 2 h(T₃), 4 h(T₄), 12 h(T₅), 24 h(T₆) after revascularization. RESULTS There was no difference among the four groups in HR, MAP, PCWP. Cardiac index (CI) in group Ⅱ, Ⅲ, Ⅳ was significantly higher at T₄-T₅ compared with groupⅠ(P<0.05); CI in group Ⅲ at T₄-T₅ was higher compared with group Ⅱ, Ⅳ (P<0.05). The concentration of plasma cTnⅠ in group Ⅱ and Ⅲ was significantly lower at T₄ compared with group Ⅰ, Ⅳ, whereas it was lower at T₅-T₆ in group Ⅱ, Ⅲ, Ⅳ compared with group Ⅰ; and in group Ⅲ, it was obviously lower than in group Ⅱ, Ⅳ. CONCLUSION Nicorandil can benefit the cardiac function and decrease myocardil injury in OPCABG patients with dose-response relationship in the hemodynamics condictions.