AIM: To observe the effect of endothelin-1 (ET-1) on the cytoskeleton protein F-actin of cultured human trabecular meshwork (HTM) cells. · METHODS: Cultured HTM cells were randomly divided into four groups: control group, low-dose ET-1 (10-9 mol/L) treatment group, middle-dose ET-1 (10-8 mol/L) treatment group, and high-dose ET-1(10-7 mol/L) treatment group. After treated with ET-1, the expression of cytoskeleton protein F-actin in trabecular meshwork was analyzed with Western-blot and the distribution of F-actin was detected with FITC-Phalloidin probe. · RESULTS: ET-1 dose-dependently and significantly increased F-actin in trabecular meshwork cells (P <0.05). The F-actin stress fiber and periphery actin fiber highly increased and manifested mild reorganization after treated with ET-1; and there were much more cell-to-cell and cell-to-extracellular matrix attachments formation in ET-1 treated HTM cells than that in the untreated HTM cells. · CONCLUSION: ET-1 promotes the expression of cytoske- leton protein F-actin and induced the trabecular meshwork actin cytoskeleton reorganization.