Objective: To explore the related factors of vascular complications after liver transplantation in children. Methods: This is a retrospective case-series research. The clinical data of 89 pediatric liver transplant patients admitted to the Organ Transplantation Center, the Affiliated Hospital of Qingdao University from January 2016 to March 2024 were collected retrospectively. This study included 44 males and 45 females,aged from 4 months to 17 years. The ratio of graft to recipient weight was 0.6% to 7.7%. The primary diseases included 48 cases of biliary atresia and 41 cases of non-biliary atresia. The t-test, Wilcoxon rank sum test, χ2 test, and Fisher's exact probability method were used for data analysis. Multivariate Logistic regression was used to analyze the related factors of vascular complications. Results: All 89 children with liver transplantation completed surgery successfully. There were 8 cases of arterial complications after surgery, including 6 cases of hepatic artery thrombosis and 2 cases of hepatic artery stenosis. There were 16 cases of portal vein complications after surgery, including 9 cases of portal vein stenosis and 7 cases of portal vein thrombosis. The results of univariate analysis showed that the age of the recipient ≤1 year was the relevant factor for hepatic arterial complications(χ2=4.772,P=0.029). The age of the recipient ≤1 year, the age of the donor, the hepatic phase, and the time of cold ischemia were the relevant factors for the occurrence of portal vein complications(χ2=7.270,Z=388.500,Z=838.000, Z=594.500;all P<0.05). The results of multivariate analysis showed that age(≤1 year vs. >1 year) and duration of cold ischemia(every additional 1 hour) were independent related factors for portal vein complications after liver transplantation in children(both P<0.05). Conclusion: Children aged ≤1 year and with prolonged cold ischemia are more likely to develop portal vein complications after liver transplantation.