Abstract: Based on the statistical analysis of regional torrential rain events,a rapid assessment model of torrential rain event was established by the controlling factors(average precipitation,rain intensity and cover range),and the distance function was employed.These factors were normalized and divided into different degrees according to the probability density function of the normal distribution.The weights of the controlling factors were determined by the movement of definition area(DA).In terms of the assessment model,3 regional torrential rain events during the flood season in 2005 were assessed.The results showed that the model was suitable for the assessment of torrential rain event.