Abstract: Liver fibrosis is a common scarring response to virtually all forms of chronic liver injury and is characterized by excessive accumulation of extracellular matrix. Excessive activation of hepatic stellate cells (HSCs) is a key step in liver fibrogenesis. The withanolide extract of Physalis angulata (WEP) is a physalin-type withanolide enriched partition from Physalis angulata. In this study, liver fibrosis mice models were established by CCl₄ and bile duct ligation (BDL) in vivo. Transforming growth factor-β1 (TGF-β1) was given in vitro to induce activation of human hepatic stellate cells LX-2 and treated with WEP at different concentrations. All animal experiments in this paper have been approved by the Ethics Committee of China Pharmaceutical University. The in vivo results showed that, compared with the CCl₄ or BDL group, WEP could reduce collagen deposition and liver damage, and reduce the levels of aspartate transaminase (AST) and alanine transaminase (ALT) in serum. In vitro, WEP had no significant cytotoxicity to LX-2 cells, but significantly reduced the mRNA and protein expressions of fibrotic markers collagen type Ⅰ α 1 chain (COL1A1) and α-smooth muscle actin (α-SMA) and inhibited the activation of hepatic stellate cells. In addition, WEP inhibited the expression of yes-associated protein (YAP) and the phosphorylation level of Smad family member 2 (Smad2) in vivo and in vitro. In conclusion, WEP can inhibit hepatic stellate cells activation via regulating the YAP and TGF-β-Smad pathways, and shows promising anti-fibrosis activity in vitro and in vivo.