Abstract: The favourable synoptic situation and climate background for a sandstorm process, which occurred in the period from the 9th to the 16th of April 1988, has been studied through analyzing weather maps, meteorological elements, satellite cloud pictures and sandstorm trajectories. The sand dust origin area, the directions and the paths of sand dust transportation and the extent the sand dust reached were also investigated. The results of measurments and analysis indicate that the concentration of sand dust particles is 10 times greater tb.an the normal. It is also shown that the elements in the sand dust are lithophile and come from natural source through the chemical composition analysis of the sand dust, so that the sand dust has not been seriously polluted by human activities.