A operational system of real-time mesoscale numerical weather forecast is developed based on SJ-100 Cluster System of parallel computing. By acquiring the 48 hour forecast of T106 numerical weather simulation and surface and radiosonde observations,including sea surface temperature and local surface observations, the NCAR/PSU MM5 model is running over three nesting domains of 135, 45 and 15 km grid length. The quasi-operational experiment has been conducted since January 2001 with 12 hour FDDA prior to the initial time on a cluster composed by 8 Intel PⅢ-800 CPU. The system displays considerable capability for regional short range weather forecast of precipitation, temperature, wind, moisture at the surface layer. The forecast productions consist of various weather elements and phenomena with quantitative analyses, timing and locations and are displayed in the form of graphics, table and text.