Abstract: Objective　To investigate the role of heat shock protein 70 (HSP70) in liver fibrosis in infants with biliary atresia (BA) and its impact on prognosis. Methods　Fourty-six (46) cases of infants with BA undergoing elective Kasai surgery were selected. In the same period, 30 cases of children with choledochal cyst and 17 cases of children with portal vein cavernous transformation were selected. The expressions of HSP70 in liver tissues were detected using immunohistochemical staining. The liver fibrosis in children with BA was detected using Sirius red-saturated picric acid staining. The expressions of HSP70 proteins in different fibrotic liver tissues were detected by using double staining. All postoperative BA infants were followed up and ended at June 30, 2016. Results　The proportion of high expression of HSP 70 proteins in BA infants were significantly higher than that in children with choledochal cyst and vein cavernous transformation (P<0.05). Rank correlation analysis showed that the expressions of HSP70 in liver tissues were positively correlated with the degree of liver fibrosis (r=0.861, P<0.05). 15 patients died among 46 cases of BA infants. The survival rate in BA children with mild liver fibrosis was 82.4%, which was significantly higher than 58.6% in the severe group (P<0.05). The survival rate in HSP70 protein low expression group was 85.0%, while in HSP70 protein high expression group was 53.8%. Kaplan-meier survival analysis showed that the median survival time in the HSP70 protein low expression group was (34.0±2.6) months, while in the HSP70 protein high expression group was (18.3±2.2) months, the difference was statistically significant (χ2=4.765, P=0.029). Conclusions　The expressions of HSP70 proteins in liver tissues in infants with BA were high and were positively correlated with the degree of hepatic fibrosis. It suggested the possible involvement of HSP70 in the process of liver fibrosis. The upregulated expressions of HSP70 often indicated poor prognosis in children. It could be used as determining biomarker for prognosis.