〔Abstract〕 Objective To investigate the molecular mechanism of Toll-like receptor 4(TLR4)/Ras homologue A(RhoA) signaling pathway involved in regulating the effect of septic serum on vascular endothelial cell permeability before and after continuous hemofiltration. Methods The serum of 5 patients with sepsis before and after continuous hemofiltration treatment was collected, and the levels of inflammatory cytokines in serum before and after hemofiltration were detected.Human umbilical vein endothelial cells(HUVEC) were treated with serum before and after continuous hemofiltration for 24 hours. The expression of VE-cadherin, F-actin, TLR4 and RhoA in vascular endothelial cells were detected by Western blot. A TLR4 low expression cell line was constructed to detect the effect of TLR4 low expression on the expression of VE-cadherin, F-actin and RhoA and the permeability of endothelial cells.Results After continuous blood treatment, the serum levels of TLR4, RhoA, interleukin-1(IL-1), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) significantly decreased. The expression levels of VE-cadherin, F-actin, TLR4 and RhoA in the serum intervention group after continuous hemofiltration treatment significantly decreased, and the cell permeability significantly decreased. Low expression of TLR4 significantly promoted the expression of VE-cadherin and F-actin, and inhibited the expression of RhoA protein.Conclusion TLR4/RhoA signaling pathway is involved in the regulation of changes in vascular endothelial cell permeability induced by septic serum after continuous hemofiltration treatment.