Objective:To investigate the relationship between preoperative high-sensitivity C-reactive protein (Hs-CRP) levels and clinical outcomes of patients undergoing off-pump coronary artery bypass graft (OPCABG) surgery.Methods:We prospectively selected 123 patients who received OPCABG at Beijing Anzhen Hospital from January 2019 to October 2019, and collected relevant preoperative and postoperative data. Patients were divided into a normal Hs-CRP group(78 cases) and an elevated Hs-CRP group(45 cases)according to the cutoff value (2 mg/L) of Hs-CRP level. The data of the two groups were compared, and regression analysis was performed on the postoperative data with differences to define independent factors.Results:The leukocyte count in the Hs-CRP group was significantly higher than that in the normal Hs-CRP group[(6.5±1.6)×10 9/ml vs. (7.4±2.1) ×10 9/ml, t=-2.839, P=0.005]. In the elevated Hs-CRP group, proportion of patients with atrial post-CABG atrial fibrillation (38% vs. 19%, χ2=5.100, P=0.024), duration of hospitalization[(21.2±7.1)days vs.(16.0±4.6)days, t=-4.469, P=0.000], hospital costs[(143.1±30.7)×10 3 yuan vs. (123.7±21.8)×10 3 yuan, t=-4.090, P=0.000]were significantly higher than those in the normal Hs-CRP level group. Smoking ( OR=1.660, 95% CI: 1.186-1.993, P=0.031) and Hs-CRP ( OR=1.170, 95% CI: 1.050-1.294, P=0.007) were independent risk factors for post-CABG atrial fibrillation. Hs-CRP ( B=0.436, 95% CI: 0.197-0.675, P=0.000) and left ventricular ejection fraction (LVEF, B=-0.180, 95% CI: -0.289--0.071, P=0.001) were independent influencing factors of duration of hospitalization. Hypertension ( B=-11.256, 95% CI: -20.670--1.842, P=0.020), Hs-CRP( B=1.235, 95% CI: 0.217-2.254, P=0.018) and LVEF ( B=-1.168, 95% CI: -1.634--0.702, P=0.000) were independent influencing factors of hospital costs. Conclusion:The preoperative Hs-CRP level of OPCABG is an independent influencing factor of post-CABG atrial fibrillation, duration of hospitalization and hospital costs. This finding lays the foundation for Hs-CRP combined with other indicators to accurately predict the prognosis of OPCABG and screen high-risk patients.