OBJECTIVE： To explore the influence of dextral metoprolol on immunologic function and nicrocirculation of patients undergoing lung cancer surgery. METHODS： 88 patients undergoing selective lung cancer surgery were selected and divided into observation group and control group  according to random number method， with 44 cases in each group. Observation group was given intravenous infusion of dextral metoprolol with loading dose of 1 μg/kg 10 min before anesthesia induction， then at 0.6 μg/（kg·h） until closing the chest； control group was given constant volume of 0.9％ Sodium chloride injection with intravenous infusion. The levels of CD3+， CD4+， CD8+ and CD4+/CD8+， as well as the TPI， LF/HF ratio were observed in 2 groups at the beginning of anesthesia induction （T0）， immediately after the end of surgery （T1）， 12 h after surgery （T2）； the occurrence of ADR were compared between 2 groups. RESULTS： There was no statistical significance in the levels of CD3+， CD4+， CD8+， CD4+/CD8+， TPI and LF/HF between 2 groups at T0 （P＞0.05）. At T1 and T2， CD3+， CD4+， CD4+/CD8+ and TPI of control group were decreased significantly and lower than those of observation group； CD8+ in control group were increased significantly and higher than observation group； LF/HF of both groups were deereased significantly， and the observation group was significantly lower than the control group， with statistical significance （P＜0.05）. There was no statistical significance in CD3+、CD4+、CD8+、CD4+/CD8+ and TPI of observation group before and after treatment （P＞0.05）. There was no statistical significance in the incidence of ADR between 2 groups （P＞0.05）. CONCLUSIONS： Dextral metoprolol can effectively improve the immunologic function and microcirculation of patients during lung cancer surgery with good safety.