Abstract: In order to investigate the effects of porcine Pseudorabies virus（PRV） infection on the brain cell cycle and related factors in mice, 40 6-week-old Balb/c mice were randomly divided into control group and 36h, 48h, and 60h groups. The test group was inoculated subcutaneously with 200 μL of PRV solution at a level of 1×10~3 TCID₅₀/100 μL, and the control group was injected with an equal amount of normal saline. The experiment used flow cytometry to detect brain cell cycle changes, and real-time fluorescence quantitative PCR and Western-blot to detect the expression of cell cycle-related factor genes and proteins, respectively. The results showed that compared to the control group, at 36 h after PRV infection, the proportion of cells in the G0/G1 phase was highly significantly higher and the proportion of cells in the S phase was highly significantly lower（P＜0.01）. At 36 h after PRV infection, the relative expression of CDK4 and CDK6 genes significantly and very significantly decreased（P＜0.05, P＜0.01）, and returned to control group levels at 60 h（P＞0.05）. At 36, 48 h after PRV infection, the relative expression of cyclin D gene was highly significantly reduced（P＜0.01）.While at 36 h after PRV infection, the relative expression of cyclin E gene increased significantly（P＜0.05） and highly significantly increased at 60 h（P＜0.01）. In addition, At 36 h after PRV infection, the relative expression of CDK4 and CDK6 proteins was down-regulated; at 36 and 48 h after PRV infection, cyclin D protein was in down-regulated expression and was slightly up-regulated at 60 h post infection; while throughout the observation period, cyclin E protein was in up-regulated expression. This study suggested that at the early stage of PRV infection, the host could block the cell cycle in G0/G1 phase by regulating the interaction among various cytokines.