Objective:To investigate the effect of HHI-Ⅰ(活血化瘀注射液Ⅰ号) on the cerebral microcirculation,the blood-brain barrier permeability in rats and anti-hypoxic activity in mice.Methods:(1) The blood microcirculation of the brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma.(2) The protective action of HHI-Ⅰagainst the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran(10%,9 mL/kg) was observed.(3) The protective effect of HHI-Ⅰagainst lethal hypoxia in mice was observed with a hypoxic chamber containing 5%oxygen.(4) The disruption of the blood-brain barrier(BBB) permeability in rats was caused by phenylephrine-induced hypertension,and the effect of intravenous injection of HHI-Ⅰon the BBB permeability was determined using Evans blue as the marker.Results:HHI-Ⅰcould increase the blood flow of the cerebral microcirculation in rats and possess some protective effects on the brain microcirculatory disturbance.Besides,HHI-Ⅰcould decrease the brain edema occurring in the process of lethal hypoxia in mice. While increasing the blood flow of brain,HHI-Ⅰcould lower the BBB permeability in rats.Conclusion:HHI-Ⅰhas several beneficial effects on the cerebral microcirculation,blood-brain barrier in rats and anti-hypoxic activity in mice. Objective:To investigate the effect of HHI-I(活血化瘀注射液一号) on the cerebral microcirculation,the blood-brain barrier permeability in rats and anti-hypoxic activity in mice.Methods:(1) The blood microcirculation of the The brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma. (2) The protective action of HHI-Iagainst the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran (10 %,9 mL/kg) was observed.(3) The protective effect of HHI-Iagainst lethal hypoxia in mice was observed with a hypoxic chamber containing 5%oxygen.(4) The disruption of the blood-brain barrier(BBB) ​​permeability In rats was caused by phenylephrine-induced hypertension, and the effect of intravenous injection of HHI-Ion the BBB permeability was determined using Evans blue as the marker.Results:HHI-Icould increase the blood flow of the cerebral microcirculation in rats and p Ossess some protective effects on the brain microcirculatory disturbance.Besides,HHI-Icoulddecrease the brain edema occurring in the process of lethal hypoxia in mice. While increasing the blood flow of brain,HHI-Icould lower the BBB permeability in rats.Conclusion:HHI -Ihas several beneficial effects on the cerebral microcirculation,blood-brain barrier in rats and anti-hypoxic activity in mice.