The display system of weather radar 3D mosaic products, which combined with the Volume Rendering Algorithm is a displaying platform on VTK (Visualization Toolki t). The platform aimed at weather radar 3D mosaic products, which is developed b y State Key Laboratory of Severe Weather of Chinese Academy of Meteorological Sc iences. By taking into account the demand of realtime processing and postana lysis, it realized the radar reflectivity display of any plane, including the X, Y, Z planes. Using raycasting algorithm, it realized the three dimensional re construction of radar reflectivity. Combining with 2D display of products and in teraction function of 2D and 3D, it comprehensively displayed the spatial distri bution of the radar echo, and made the advantages of 3D mosaic products into ful l play.