Abstract: Objective:To explore the value of diagnosis and differential diagnosis of prostate cancer by functional magnetic resonance imaging(fMRI). Methods:The data of 50 cases with prostatic diseases, surgical pathology and the clinical treatment were analysed. All cases were checked by fMRI, diffusion weighted imaging(DWI) and spectrum and dynamic enhanced scanning on the basis of conventional scanning. Results:The DWI of prostate cancer were hyperintensities, its ADC map was low signal and the mean values of ADC were lower than(897. 4 67. 5) 10－6. The peak value of choline(Cho) increased and citrate(Cit) decreased were showed on spectrum, and the ratio of［Cho + creatine(Cre) /Cit］of the tumor tissue was increased,which was 2. 75 0. 83. Dynamic increase in early period was obvious strengthening and time-signal intensity curve of DCE-MRI was mainly the outflow type or terrace type. Conclusions:The application of fMRI can improve the detection rates of prostate cancer and diagnosis, so it has high clinical value.