AIM: To investigate the effect of herbal compound 861(Cpd861) on the transforming growth factor-131 (TGFβ1)/activin receptor-like kinase 1 (ALK1, type I receptor)signaling-pathway-related gene expression in the LX-2 cell line, and the inhibitory mechanism of Cpd861 on the activation of LX-2 cells.METHODS: LX-2 cells were treated with TGFβ1(5 ng/mL) Cpd861 (0.1 mg/mL), TGFβ1 (5 ng/mL) plus Cpd861 (5 ng/mL) for 24 h to investigate the effect of Cpd861 on the TGFβ1/ALK1 pathway. Real-time PCR was performed to examine the expression of α-SMA (α-smooth muscle actin), ALK1, Id1 (inhibitor of differentiation 1). Western blotting was carried out to measure the levels of α-SMA and phosphorylated Smadl,and immunocytochemical analysis for the expression of α-SMA.RESULTS: In LX-2 cells, TGFβ1/ALK1-pathway-related gene expression could be stimulated by TGFβ1, which led to excessive activation of the cells. Cpd861 decreased the activation of LX-2 cells by reducing the expression of α-SMA mRNA and protein expression. This effect was related to inhibition of the above TGFβ1/ALK1-pathwayrelated expression of genes such as Id1 and ALK1, and phosphorylation of Smad1 in LX-2 cells, even with TGFβ1 co-treatment for 24 h.CONCLUSION: Cpd861 can restrain the activation of LX-2 cells by inhibiting the TGFβ1/ALK1/Smad1 pathway.