Abstract: By analysing the time and space variations of the meteorological elements in the course of a heavy sandstor m, the essay surveys the relationship sandstorm and the movement of the cold air. It points out that the cold air which forms the sandstorm in Spring in the Gansu Corridor finds its way over Tianslzan Mountains through the southern part of Xinjiang Uighur Autonomous Region down into the Gansu Corridor. Having studied the circulation, the speed the day variance and the slope of the cold front, and giving emphasis on the important role of the heat element in the course of the sandstorm, the essay points out that. The sandstorm provides itself with positive regenerative machine and intensifies in the day-time. In the evening, it provides itself with negative regeneration and subsides quickly. A positive regenerative model of the outbreak and development of the sandstorm and a focal point in its forecast are given.