〔Abstract〕 Objective To investigate the role of Glutathione peroxidase 2(GPX2) in the occurrence and progression of intrahepatic cholangiocarcinoma(ICC). Methods The Omicshare website was used to analyzeGPX2expression levels in ICC. The expression levels in ICC were validated using quantitative real-time reverse transcription PCR(RT-qPCR), Western blot, and immunohistochemistry. Stable GPX2 knockdown and overexpression HuCCT1 cell lines were constructed. The effects of GPX2 on ICC cell proliferation, migration, apoptosis, and epithelial-mesenchymal transition(EMT) were investigated using colony formation assays, cell counting kit-8(CCK-8) assays, wound healing assays, Transwell assays, and flow cytometry. A mouse model of cholangiocarcinoma was constructed to assess GPX2 expression in mouse cholangiocarcinoma tissues. Results Based on the analysis results from the Omicshare website,GPX2was generally upregulated in intrahepatic cholangiocarcinoma(ICC)(P<0.001). Western blot(P<0.000 1), RT-qPCR(P<0.001), and immunohistochemistry experiments showed that, compared to adjacent non-cancerous tissues, the expression of GPX2 was significantly elevated in ICC. When GPX2 was knocked down, the colony formation rate of cells decreased significantly(P<0.01), and the proliferation capacity was reduced(P<0.001). Conversely, overexpression of GPX2 led to a significant increase in colony formation rate(P<0.01) and enhanced proliferation capacity(P<0.01). Results from wound healing and Transwell assays demonstrated that GPX2 knockdown slowed down cell wound healing(P<0.01) and reduced migration ability(P<0.01). Additionally, GPX2 knockdown resulted in an increase in E-cadherin(P<0.01) and a decrease in N-cadherin(P<0.01) and Vimentin(P<0.05). On the other hand, overexpression of GPX2 accelerated wound healing(P<0.05) and enhanced migration ability(P<0.05), while E-cadherin expression decreased(P<0.05) and N-cadherin(P<0.01) and Vimentin(P<0.001) expression increased. Flow cytometry for apoptosis and Western blot experiments indicated that GPX2 knockdown increased the apoptosis rate(P<0.001), decreased the expression of Bcl-2(P<0.001), and increased the expression of BAX(P<0.01). But overexpression of GPX2 reduced the apoptosis rate(P<0.01), increased Bcl-2 expression(P<0.000 1), and decreased BAX expression(P<0.001). Finally, elevated levels of GPX2 were observed in a mouse model of cholangiocarcinoma. Conclusion GPX2 is highly expressed in human and mouse cholangiocarcinoma tissues, and it may enhance cholangiocarcinoma cell proliferation and migration, promote tumor cell EMT, and inhibit tumor cell apoptosis.