Objective To explore the best parameters of the magnetic resonance diffusion - weighted imaging(DWI) sequence in diagnosis of abdominal diseases,to get the best examination of DWI by comparing two kinds of images.Methods To scan the abdomens of 20 volunteers by Epse - DWI sequence of 3T MR from siemens by adjusting the different parameter values of b,TR,NEX,respiratory way respectively.The value of ADC,quality index and SNR as the indicators for statistical analysis.Ten patients with abdominal tumor were examined by the two kinds of diffusion weighed imaging with background suppression.Results ( 1 ) In the sequence of Epse - DWI,①when the augmentation of b value,the value of ADC,quality index and SNR were diminished,but b value as 200,400,600,the image quality index difference in 800,1000 smaller than the latter,and the latter' s SNR significantly to bring down.②With the augmentation of TR,the changes of the ADC value,SNR and the quality index were relatively small.③With the augmentation of NEX,there were significant difference in SNR and the quality index.④There were obvious differences between respiratory gating and still breathing image.(2)The imaging of inversion - recovery background suppression is better,but the structure of 3D imaging is poor;SPAIR fat suppression could display the image opposite with the former.Conclusions As b =600,TR =2500,NEX =4,respiratory gating can get high quality image of the abdomen DWI by Epse - DWI sequence of 3T MR.Tumor screening by using the sequence of Epse - DWI with inversion - recovery background suppression firstly.The diseased part of the abdomen or regular inspection by using the sequence of Epse - DWI with SPAIR fat suppression.