【Abstract】Objective: To construct models of C57BL/6N and BALB/C mice infected with vaccinia virus VR-1354 (WR (NIH TC-adapted)), and compare the differences between the C57BL/6N mouse and BALB/C mouse infection models. Methods: According to the conventional method, vaccinia virus VR-1354 was amplified, concentrated and titrated. The median lethal dose (LD50) of vaccinia virus VR-1354 for C57BL/6N mice and BALB/C mice was determined respectively. Mice of the two strains were infected with the LD50 respectively. The lung tissues of the control group and the experimental group mice were taken for HE staining on the 3rd, 7th and 14th days, and the changes in the virus load in the lung tissues were measured at the same time. Results: (1) The titer of the amplified vaccinia virus VR-1354 was 3 × 10? PFU/mL. (2) The LD50 of vaccinia virus VR-1354 for C57BL/6N mice was 2.5 × 103 PFU, and the LD50 for BALB/C mice was 2.8 × 103 PFU. (3) After infecting mice of the two strains with 2.5 × 103 PFU of vaccinia virus VR 1354, the lung tissue lesions of the mice became more serious as the infection time increased, but the symptoms of the mice tended to recover after the seventh day. (4) The virus loads in the lung tissues of the two strains of mice began to increase on the 3rd day, reached the maximum on the 7th day, and then gradually decreased. Conclusion: The infection models of C57BL/6N mice and BALB/C mice infected with vaccinia virus VR-1354 were successfully established. This virus can cause obvious lesions in the mouse lung tissues, including inflammatory cell infiltration and alveolar cavity fluid exudation, etc. There are certain differences in the degree of disease onset and susceptibility between the two strains of mouse infection models. The susceptibility of C57BL/6N mice to this virus is higher than that of BALB/C mice.