Abstract: Biliary atresia is one of the most serious digestive system diseases, which is threatening the health of infants, and liver fibrosis is a major cause of death in children. In the process of the pathogenesis of biliary atresia, virus damage the body induced a series of immune and inflammatory reaction results in a decrease of regulatory T cells (Treg cells); high expression of CD14, activating a variety of inflammatory pathways and TGF-β/Smad2/3 pro-fibrogenic pathway, produced a large number of medium damage of liver cells and bile duct cells, release of proinflammatory factor, oxygen metabolism matter and cytokines, etc., which further damage hepatobiliary system; Imbalance of internal environment with liver parenchyma cells, hepatic macrophages, gathered in the liver of inflammatory cells, being such as adaptive degeneration, necrosis, hyperplasia, activating hepatic satellite cells (HSCs) and then HSCs into fibroblasts promote the process of liver fibrosis. Immune and inflammatory lesions, pro-fibrogenic pathway are the important factors in contributing to liver fibrosis and cirrhosis of biliary atresia.

Key words: biliary atresia, liver cirrhosis, T-lymphocytes, regulatory, transforming growth factor beta, antigens, CD14, Smad proteins