To observe the protective effect of fasudil hydrochloride against acute renal injury in septicopyemia rats. A total of 60 Wister rats were included in the study and divided into control group (n=10), model group (n=25) and treatment group (n=25). Model group and treatment group received intraperitoneal injection of endotoxin (ET) to establish acute renal injury models while the control group only received daily intraperitoneal injection of normal saline 1mL. Five rats were taken out of model group and treatment group respectively at 1h (T1), 6h (T2), 12h (T3), 24h (T4) and 48h (T5), for intraperitoneal injection of ET 30mg/kg. Treatment group received intraperitoneal injection of fasudil hydrochloride 30mg/kg 1h before injection of ET. For three groups, 5mL blood samples were collected from postcava for determination of serum creatinine and urea nitrogen levels at different time points. Concentrations of serum tumor necrosis factor α and ET-1 were determined by using ELISA. The renal pathologic changes were observed under the microscope. Serum creatinine levels in both model group and treatment group were significantly higher than control group at T2-T5 (P<0.05) while the levels in treatment group were significantly lower than control group at T3-T5 (P<0.05). At T2-T5, blood urea nitrogen levels in model group and treatment group were significantly higher than control group (P<0.05) while the levels in treatment group were significantly lower than model group at T3-T5 (P<0.05). Concentrations of serum tumor necrosis factor α in model group and treatment group were significantly higher than control group at T1-T5 (P<0.05) while the levels in treatment group were significantly lower than model group at T1-T5 (P<0.05). Serum ET-1 concentrations in model group and treatment group were significantly higher than control group at T1-T5 (P<0.05) while the levels in treatment group at T1-T4 were significantly lower than model group (P<0.05). Rats in control group showed no swelling or hyperemia in kidney cells but normal structure and normally arranged renal tubular epithelial cells. Obvious injury was observed in model group at T3 and renal tubular epithelial cells in disorder and at swelling condition, hyperemia and angiectasis in glomerulus, degenerative opacities and vacuolar degeneration, and maximized injury were observed at T4. Injury in renal tissue in treatment group was significantly milder than model group. Fasudil hydrochloride has the significantly protective effect against acute renal injury in septicopyemia rats.