Abstract: In order to research on virosome distribution in different ventilated swine pens, the air flow movement and virosome concentration and deposition in two kinds ventilation of swine pens were studied by numerical simulation in this paper. Virosomes trajectory was simulated by discrete trajectory model based on standard k—ε turbulence model. The results showed that in the same air supply and pressure conditions and particle properties, compared with the vertical ventilation, the horizontal ventilation could better control the virus particle diffusion. Although the vertical ventilation enabled better contaminant removal effectiveness, more particles escape and fewer suspended particles, there were more particle deposition which could cause secondary pollution. The two ways have their own advantages in different perspectives. From the standpoint of controlling the virus spread and cross-infection，horizontal ventilation is better than vertical ventilation since virus particles can be better controlled in horizontal ventilation and it is easy to form a more uniform flow. Vertical ventilation will make the virus particles widespread diffusion, easy to cross-infection.