Objective To construct mouse models of vaccinia virus infection using C57BL / 6N and BALB/ C mice infected with vaccinia virus VR-1354 (WR (NIH TC-adapted)), and to compare the differences between the models in the two mouse strains. Methods Vaccinia virus VR-1354 was amplified, concentrated, and titrated, according to conventional method. The median lethal doses ( LD₅₀ ) of vaccinia virus VR-1354 for C57BL / 6N and BALB/ C mice were determined, respectively, and mice from the two strains were infected with the respective LD50.Lung tissues from control and experimental mice were removed for hematoxylin and eosin staining on days 3, 7, and 14, and changes in the virus load in the lung tissues were measured at the same times. Results The titer of the amplified vaccinia virus VR-1354 was 3×10⁸plaque-forming units (PFU) / mL. The LD₅₀values in C57BL / 6N andBALB/ C mice were 2. 5×10³and BALB/ C 2. 8×10³PFU, respectively. After infecting mice from both strains with2. 5× 10³PFU of vaccinia virus VR 1354, lung tissue lesions worsened with increasing infection time, but the symptoms of the mice tended to recover after day 7. The virus loads in lung tissues began to increase on day 3 in both strains, peaked on day 7, and then gradually decreased. Conclusions C57BL / 6N and BALB/ C mouse models infected with vaccinia virus VR-1354 were established successfully. The virus can cause obvious lesions in mouse lung tissues, including inflammatory cell infiltration and alveolar cavity fluid exudation. The degree of disease onset and susceptibility differed between the two mouse strains, with C57BL / 6N mice showing higher susceptibility to this virus than BALB/ C mice.