Abstract: Objective:To explore the effects of tetramethylpyrazine(TMP) on the levels of RhoA, Rho associated coiled coil forming protein kinase 2(ROCK2), myosin light chain(MLC) phosphorylation and ezrin-radxin-moesin(ERM) phosphorylation in the injury of human umbilical vein endothelial cells(HUVECs) induced by lipopolysaccharide(LPS).Methods:The HUVECs were cultured in vitro, and divided into the control group, LPS group and TMP groups(0.5, 1.0, 1.5 mg/mL).The mRNA levels of RhoA, ROCK2 and p-EZR in endothelial cells were detected by real-time fluorescence quantitative PCR, and the protein levels of RhoA, ROCK2, p-MLC and p-ERM were examined using western blotting.Results:Compared with the control group, the protein levels of RhoA, ROCK2, p-MLC and p-ERM, and the mRNA levels of RhoA, ROCK2 and p-Ezr in LPS group significantly increased(P<0.01).The differences of the protein and mRNA levels of RhoA between LPS group and 3 TMP groups were not statistically significant(P>0.05).Compared with the LPS group, the protein levels of ROCK2, p-MLC and p-ERM, and the mRNA levels of ROCK2 and p-Ezr decreased significantly in 3 TMP groups(P<0.01).The differences of the expression of ROCK2, p-MLC and p-ERM within 3 TMP groups were statistically significant(P<0.05 to P<0.01).Conclusions:TMP may protect the HUVECs against LPS-induced injury by inhibiting the expressions of ROCK2, p-MLC and p-ERM in Rho/ROCK signaling pathways, and reducing the injury of LPS on endothelial cell skeleton.