Objective:To evaluate the effects of remazolam on sublingual microcirculation during anesthesia induction in the patients undergoing off-pump coronary artery bypass grafting under general anesthesia.Methods:Forty-two patients of both sexes, of American Society of Anesthesiologists Physical Status classification Ⅲ or IV, aged 45-75 yr, with body mass index of 18-30 kg/m 2, undergoing off-pump coronary artery bypass grafting under total intravenous anesthesia, were divided into 2 groups ( n=21 each) using a random number table method: propofol group (group P) and remazolam group (group R).Remazolam 0.15-0.35 mg/kg was intravenously infused in group R, and propofol 1.5-2.0 mg/kg was intravenously infused in group P, when patients lost consciousness and they did not response to shoulder tapping, the maintenance dose was adjusted as follows: remazolam 0.15-0.30 mg·kg -1·h -1 in group R and propofol 2.0-4.0 mg·kg -1·h -1 in group P. The BIS value was maintained at 45-55 during operation in the two groups.The proportion of perfused vessels for all vessels (PPV (all)), proportion of perfused small vessels (PPV (small)), perfused vessel density of all vessels (PVD (all)), and perfused small vessel density (PVD (small)) were recorded before induction (T 1), immediately after intubation (T 2) and 30 min after intubation (T 3).The cardiovascular events were recorded during anesthesia induction. Results:Compared with the baseline at T 1, PPV (all), PPV (small) and PVD (all) were significantly decreased at T 3 ( P<0.05), and no significant change was found in PPV (all), PPV (small), PVD (all) and PVD (small) at T 2 in group P ( P>0.05), and no significant change was found in PPV (all), PPV (small), PVD (all) and PVD (small) at T 2 and T 3 in group R ( P>0.05).Compared with group R, PPV (small) was significantly decreased at T 3 in group P ( P<0.01). Conclusions:Remazolam exerts less inhibitory effect on sublingual microcirculation than propofol during anesthesia induction in the patients undergoing off-pump coronary artery bypass grafting.