Abstract: OBJECTIVE To investigate the protective effect of icariin on F-actin damage of osteoblast cytoskeleton and the regulation of related signaling pathways. METHODS Lipopolysaccharide(LPS) was used to induce osteoblasts to establish an injury model in vitro. Experimental group:control group, model group and 0.1, 1, 10 μg·mL^-1 icariin groups. MTT method was used to observe the effect of icariin on the activity of osteocytes. TRITC-Phalloidin fluorescence staining was used to observe the effect of icariin on cytoskeleton. ELISA method was used to determine the content of F-actin in osteocytes. RT-PCR method was used to determine the expression of cytoskeleton-related factors Rho A and Cofilin mRNA. RESULTS Compared with the control group, 100 μg·mL^-1 LPS could significantly reduce the survival rate of osteoblasts(P<0.01). Compared with the model group, the survival rate could significantly improve after pretreatment with 1-10 μg·mL^-1 icariin(P<0.05 or P<0.01), while 0.1 μg·mL^-1 icariin had no significant effect. Compared with the model group, 1-10 μg·mL^-1 icariin could significantly inhibit F-actin depolymerization in osteoblasts(P<0.05), inhibit the mRNA expression of Rho A (P<0.05 or 0.01), and icariin at concentration of 0.1-10 μg·mL^-1 could inhibit the mRNA expression of Cofilin (P<0.01).CONCLUSION Icariin has protective effect on LPS-induced cytoskeleton F-actin injury model, and its mechanism may be related to inhibiting the expression of cytoskeleton-related factors Rho A and Cofilin mRNA.