Abstract: Nearly 20 megaton sulfuric aerosols were erupted to the stratosphere during mid-June of 1991. It is the strongest event with maximal volcanic clouds since the beginning of present century. The dispersion of volcanic clouds in the stratosphere and their cooling effect on large scale climate in 1992 is discussed. It is shown that the global average temperature has pronounced drop, and the climatically cool regions in northern summer-autumn of 1992 appear significant from the tropics to higher latitudes. Furthermore, a series of cool injury events appeared in the summer of the year in China.