A severe hailstorm occurred in Shandong Province is simulated with the t hreedimension convection cloud model. The simulated results are compared with the Dopp ler weather radar observations. The wind field, radar echo and microphysics stru cture of the hailstorm are studied. The findings show that location of hail embr yo lies in front of the main updraft, at the turning of updraft to divergence do wndraft, and above the largest ascending velocity in the vertical direction. Ice particles collide with supercooled water to form graupel and hail particles, and the hail particles grow between the ascending and sinking currents. The find ings are valuable in the actual operations of hail suppression.