Abstract: Combined with related literatures, the diagnosis and treatment of a premature infant with arterial thrombosis were discussed. The infant developed arterial embolism of right limb due to mistakenly insertion into axillary artery during axillary vein catheterization and continuous blood transfusion, and was conducted with targeted treatments such as local nitroglycerin smear, anticoagulation by low molecular weight heparin calcium, and thrombolysis by urokinase. The vessel recanalized, the symptoms disappeared, and no adverse reactions occurred after 18 days. Neonatal arterial thrombosis can cause serious consequences, strengthening the understanding of the disease and recognizing the disease earlier are needed, and the infant can be cured by actively implementing local vasodilation combined with anticoagulation and thrombolysis.