Abstract: Aerosol deposition in different thermal conditions was calculated with sectional method model, and effects of four natural deposition mechanisms on various aerosol diameters were analyzed. The result shows that diffusiophoresis deposition of aerosol is the most affected by thermal condition. According to the feature of passive containment cooling of AP series pressurized water reactor, the reduction of radioactivity in severe accident conditions can be enhanced through decreasing the temperature of containment wall to improve diffusiophoresis deposition of aerosol.