Objective To analyze the clinicopathological characteristics and intrahepatic immune cells infiltration condition after Kasai biliary atresia surgery. Methods Data of 28 cases who underwent liver transplantation in the liver transplantation center of our hospital from June 2017 to March 2019 were enrolled. Of which, 20 cases were in the biliary atresia group (divided into two subgroups: 10 cases without Kasai surgery and 10 cases after Kasai surgery, and latter subsided cholestasis) and 8 cases in the control group. Clinical and pathological morphological characteristics of the groups were compared. Liver tissue sections were stained with immunohistochemistry and CD3, CD4, CD8, CD20, Foxp3, and interleukin-17A were quantitatively analyzed. Kruskal-Wallis test was used to measure the above indicators, and rank-sum test or Fisher's exact test was used to compare the count data. Results The degree of clinical and pathological cholestasis in the biliary atresia group after Kasai surgery was significantly lower than that of the group without Kasai surgery, and the degree of liver fibrosis was also significantly reduced ( P < 0.05), but there was no statistically significant difference in the degree of inflammation in the portal vein area between the two groups ( P > 0.05). There was statistically significant difference in the types of immune cells infiltrated in the liver ( P < 0.05). Compared with the group without Kasai surgery, the infiltration of CD3, CD8, IL-17A and Foxp3 positive cells in the portal vein area after Kasai surgery group ( P < 0.05) was significantly reduced, but there was no statistically significant difference in the proportion of Foxp3/CD4 positive cells between the two groups ( P > 0.05), which continued to be lower than that of the control group ( P < 0.05). Compared with the non-Kasai surgery group, the proportion of Foxp3/IL-17A and Foxp3/CD8 positive cells in the portal vein area did not increase significantly after Kasai surgery group ( P > 0.05), and remained lower than the control group. However, the proportion of Foxp3/IL-17A and Foxp3/CD8 positive cells was significantly reduced ( P < 0.05). Conclusion Intrahepatic inflammatory cell infiltration and regulatory/effector T lymphocyte proportion dysregulation exist in patients with subsided cholestasis after Kasai biliary atresia surgery, which may be an important factor to promote the disease progression.