Aim To investigate the effects of fasudil hydrochloride on the injury of human umbilical vein endothelial cells(HUVEC)induced by angiotensinⅡ(AngⅡ)which influence on the expression of Rho associated kinase(ROCK)and phospho-myosin light chain(P-MLC).Methods HUVEC were incubated in vitro and treated with AngⅡ,AngⅡ+specific blocker(Y-27632),AngⅡ+fasudil hydrochloride for different time.Cell activities were detected by MTT method.Morphous and distribution changes of F-actin were observed by immunofluorescence,expression of ROCK and P-MLC were measured by Western Blotting.Results Compared with control group,AngⅡ had significant inhibitory effect on endothelial cells vigor(P><0.01),furthermore,these effects were dose-dependent(P><0.01)in the other three groups.Morphous and distribution changes of F-actin by imunofluorescence,compared with control group,the rupture of stree fibers constructed by F-actin,deformation and digitation of HUVEC were exhibited.Compared with AngⅡ group,expression of ROCK and P-MLC in the specific blocker group and the drug group were remarkably restrained(P><0.01),but higher than the control group(P><0.01).Conclusion Fasudil hydrochloride can protect the cytoskeletal of HUVEC which were induced by AngⅡ,through obviously controlling the expression of ROCK and P-MLC in the Rho/Rho kinase signaling pathways,thus weakened the damage in cytoskeletal.