A study was carried out about the duration time，scop e，and intension of the 2002 summer and autumn continuous drought  in Cransu，which long duration time and heavy intension scarcely appeared in recent 50 years. The causes of continuous drought were ainly depended on that Westerly circumfluence，and the High ridge over Baikal and Northwestern Pacific very strong ;the trough ver Southern Indian Peninsula weak; the sea levelpressure departure on the high side;sea surface temperature anomaly and El Nino ccurring. All those above together forced into continuous drought in Cransu Province.  These results were significantly to establish the reventing and reducing calamities rules and valuably to short一term climate forecast.