Background Alveolar echinococcosis （AE） is a disease in human and animals, and the cure rate is unsatisfactory. This study aimed to investigate the curative efficacy of different doses of locally applied radiotherapy on alveolar echinococcosis in rats. Methods Rats infected with Echinococcus multilocularis were randomly divided into 4 groups of 15 rats each： low-, middle-, and high-irradiation groups and a control group. Rats in the control group underwent no treatment, while rats in the irradiation groups received 6-MeV radiotherapy at 20 Gy/8 f, 40 Gy/8 f, and 60 Gy/8 f respectively, once every 3 days for a total of 8 times. One month after radiotherapy, wet weight and AE vesicle inhibitory rate were detected in rats of each group. Histopathologic and ultrastructural observations of tissues with AE lesions were performed. Results In the treatment groups, an obvious inhibitory effect was found in AE rats; the inhibitory rates were 50%, 72%, and 82%, respectively. There were also statistical differences in pathological changes and average wet weight of the lesions compared with the control group （P 〈0.05）. In the treatment groups, injuries of various degrees were found in the ultrastructure of the laminated and germinal layers in the capsular wall of AE, and injury was most severe in the high-dose group. Conclusion Radiotherapy has a dose-dependent inhibitory effect on the arowth of AE.