Feow structures of the two-phase subsonic jet impinging on a flat plate normal to flow are described focusing upon the particle size. First, the flow properties for both gas- and particle-phases are numerically solved in the region from the reservoir to the nozzle exit, and then flow fields in the free jet, impingement and wall jet regions are solved as a perturbation from the nozzle exit condition. Some of significant characteristics are pointed out for results of the numerical experiments concerning mist flows composed of air and water-droplets. The flow fields for both gas- and particle-phases strongly dependent upon the particle size. When water-droplets mixing in the mist are very small, particles after the impingement of the mixture jet on the surface travel very closely to the surface along the radial direction. With increasing particle size, rebounding particles scatter not only near the surface, but also over the almost whole computational domain. Again, the distribution of vorticity is concentrated on the boundary of mixture flow and varies according to the particle size. The flow field is not necessarily steady, but changeable in a nearly periodic manner.