Objective To investigate the effect of ulinastatin on inflammatory cytokines and cardiopulmonary function in hypoxemia patients after off-pump coronary artery bypass graft (CABG).Methods Forty hypoxemia patients, who had off-pump CABG surgery, were randomly divided into two groups, control group (n=20) and observation group (n=20).Patients in both groups accepted routine treatment.The observation group was given the treatment of ulinastatin additionally.Fractional concentration of inspired oxygen (FiO₂), heart rate (HR), mean arterial pressure (MBP), arterial oxygen partial pressure (PaO₂), plasma tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8, brain natriuretic peptide (BNP), and cardiac troponin I (cTnI) were observed at pre-treatment (T0), 4 hours after treatment (T1), 24 hours after treatment (T2), 48 hours after treatment (T3), and 72 hours after treatment (T4). Duration of ICU stay and endotracheal intubation time were also observed.Results The differences in general information between the two groups were not significant before treatment (P>0.05). The differences in HR and MBP were not significant (P＞0.05) between the two groups after treatment.Compared with the control group, OI was improved, while the serum IL-6, IL-8, IFN-α, and BNP levels all lower in the observation group after treatment (P＜0.05).There was no significant difference in cTnI at T1 between the two groups (P＞0.05), but cTnI was lower in the observation group than the control group at T2, T3, and T4 (P<0.05).Endotracheal intubation time and the duration of ICU stay of the observation group were much shorter than those of the control group (P＜0.05).Conclusion Ulinastatin treatment for hypoxemia after off-pump CABG could reduce inflammation response cardiopulmonary improve cardiopulmonary, and shorten endotracheal intubation and duration of ICU stay.