In order to determine the pathogenicity of Anguillid herpesvirus (AngHV), an AngHV strain, NA16108, isolated from “mucus sloughing and hemorrhagic septicemia disease” samples was used to study its pathogenesis to juvenile European eel, Anguilla Anguilla. The results showed that the body surface of the AngHV-injected A. anguilla had the symptoms of mucus exfoliation, fin hemorrhages, red head, etc. The diseased A. anguilla had pathological changes of mucus increase and hemorrhages of gill, discoloration of liver and swelling of spleen and kidney, etc. Further histopathological analysis showed that the skin had exfoliation of mucus and mucosa flat epithelial cells, gill had secondary lamellar hyperplasia, blood vessel hemorrhages, swelling and necrosis of respiratory cells, spleen had necrosis and aggregation of melanocytes, and kidney had necrosis wall cells and narrowing lumen of renal tubular, which are consistent with the clinical characteristics of A. anguilla "mucus sloughing and hemorrhagic septicemia disease". The mortality analysis showed that AngHV infected A. anguilla began to die from the 4th day post injection, and the cumulative mortality on the 7th and 14th day reached up to 26.7% and 56.7%, respectively. Quantitative real-time PCR analysis showed that AngHV could be detected in the liver, spleen, kidney, intestine, gill and skin mucus of AngHV infected A. anguilla, and AngHV could be re-isolated by EO cell line from the main internal organs, which indicating that the A. anguilla had a systemic infection of AngHV. The results indicated that AngHV is the pathogenic agent of "mucus sloughing and hemorrhagic septicemia disease", which laid an important foundation for further study on the pathogenesis and prevention and control of the disease.