Abstract: The text revealed the sudden rain of down-scaling northeast area Qinghai-Tibet Plateau based on 132 rain and rainstorm samples which occurred from June to August between 1990 and 2011 in the area by analyzing warm air transport, thermal fi eld, dynamic fi eld structure, weather system, strong convective cloud development situation, fl ow characteristics from surface to high level, terrain and physical distribution situation. We investigated the onset of sudden heavy rains with the number of occurrences and the data collected both at high altitudes and on the surface ground before and after the precipitation. Through a further careful analysis of the track system, the trigger mechanism and their causes of formation, we had a better understanding of such abrupt weather processes, thus initiating a new prediction method so as to improve the accuracy of our future forecast.