ObjectiveTo evaluate the application value of magnetic resonance diffusion weighted imaging (DWI)in diagnosis and differential diagnosis of prostate cancer. Methods53 Cases of suspected prostate cancer patients with elevated prostate-specific antigen, abnormaldigital rectal examination or ultrasound examination were underwent DWI examination before operation. Apparent dispersion coefficient was measured and compared to pathological results. Results There were 15 cases of prostate cancer, 37 cases of benign prostate hyperplasia and one prostatic intraepithelial neoplasia. When b =1 000 s/mm2 ,the ADC values of foci area in prostate cancer group and peripheral zone in benign prostate hyperplasia group were (0.813 ±0.25) × 10-3mm/8 and (1.45±0.24) × 10-3mm/s respectively, and the difference had statistical significance(t =-26. 117,P ＜0. 01 ). When b =60D s/mm2, the ADC values of foci area in prostate cancer group and peripheral zone in benign prostate hyperplasia group were ( 1.03 ± 0. 27) × 10-3 mm/s and ( 1.62 ± 0. 33) × 10- 3 mm/s respectively, and the difference had statistical significance( t =- 24. 191, P ＜ 0. 01 ). The area under the ROC curves was 0.862, and the sensitivity and specificity of DWI were 78.1％ and 91.5％ respectively.ConclusionDWI can provide quantitative information for prostate cancer diagnosis and differential diagnosis,therefore it possesses a good clinical application value.