Taking Jinjiang River Basin as study area,and using Morris screening method,paramtric sensitivity of HEC-HMS for flood simulation was analyzed．After calibration and validation on the basis of measured data from 1972 to 1979,a distributed flood simulation model of the basin has been established. Numerical results indicate that the major sensitivity parameters are CN,K,initial abstration and lagtime．The efficiency coefficient of the model was more than 0.8,the error time of peak flow was within three hours； whereas for multimodal floods,the efficiency coefficient was less than 0.6．The study demonstrated that HEC-HMS has a good adaptability to unimodal floods in the basin．