OBJECTIVE To explore the effects of adrenergic beta-1 antagonists on hemodynamics of severe septic patients. METHODS A total of 16 severe septic patients underwent mechanical ventilation from June 2012 to December 2012 at Fourth Affiliated Hospital of Nanchang University. There were 14 males and 2 females with a mean age of (58 ± 6) years (range: 48 - 67 years). Among them, there were multiple trauma (n = 4), acute severe pancreatitis (n = 6) and recent tumorectomy for gastrointestinal cancer (n = 6). The adrenergic beta-1 antagonist esmolol was injected through central venous catheter to reduce heart rate by 20% from baseline. Various indices (heart rate, systolic blood pressure, diastolic blood pressure, cardiac output, cardiac index, central venous pressure, pulmonary artery wedge pressure, pulmonary vascular resistance index, systemic vascular resistance index and stroke volume index) were monitored by a multifunctional and hemodynamic monitor connected to pulmonary artery catheter. And other indices of arterial pressure of carbon dioxide (PaCO2), lactate (Lac) concentration, superior vena cava oxygen saturation (ScvO2), superior vena cava carbon dioxide pressure (PcvO2) and central venous-to-arterial carbon dioxide tension difference (Pcv-aCO2) were measured by a blood-gas-analyzer before 10 minutes and after 3 hours of dosing. RESULTS Heart rate and cardiac index decreased significantly at 3 hours post-dosing compared with that at pre-dosing ((91 ± 13) vs (114 ± 15) beats per minute, (3.4 ± 0.7) vs (4.2 ± 0.8) L×min(-1)×m(-2), P < 0.05), but systolic blood pressure, diastolic blood pressure, central venous pressure, pulmonary wedge pressure, pulmonary vascular resistance index, systemic vascular resistance index and stroke index showed no significant changes ((100 ± 13) vs (108 ± 14) mm Hg (1 mm Hg = 0.133 kPa), (62 ± 7) vs (64 ± 6) mm Hg, (11.8 ± 2.5) vs (12.1 ± 2.4) mm Hg, (13 ± 5) vs (14 ± 4) mm Hg, (201 ± 72) vs (179 ± 95) dyn×s/(cm(5)×m(2)), (1360 ± 520) vs (1366 ± 538) dyn×s/(cm(5)×m(2)), (40 ± 9) vs (38 ± 6) ml/(beat×m(2)), all P > 0.05). ScvO2, Lac and Pcv-aCO2 also showed no significant change ((72.8 ± 5.3)% vs (70.1 ± 4.0)%, (2.11 ± 0.13) vs (2.31 ± 0.23) mmol/L, (3.9 ± 1.0) vs (4.5 ± 0.8) mm Hg, all P > 0.05). CONCLUSIONS Adrenergic beta-1 antagonist may reduce cardiac output in proportion to the percentage decreases in heart rate in severe septic patients without adverse effects upon cardiac function and systemic perfusion.