The spring maize was seriously influenced by drought disaster in Northwest China.Based on the risk theory and risk assessment method,the spring maize acreage and total yield of 71 counties or cities in Gansu Province during 19802011 were analyzed to explore the risk level of fluctuation and yield reduction of spring maize production in Gansu Province under arid climatic conditions.Through the discrimination of normal distribution and the normalization of skewness distribution,we studied the variation of yield reduction rates of spring maize in different years in Northwest China and analyzed the spatial distribution pattern of spring maize production disaster risk in order to provide theoretical basis for disaster prevention and reduction. The results indicated that the risk areas of different degrees scattered on the whole and contiguous in a small area,among which the highest of rate yield occurred in Hexi Area,followed by Longzhong Area;highrisk areas mainly concentrated in the eastern part of Longdong,the higher-risk areas distributed in the most parts of central and eastern Guizhou;Hexi Area can effectively alleviate drought through irrigation,and has the lower risk.The results can provide the references for predicting the risk of yield loses,resisting drought disaster and decreasing economic loses.