Objective To find out the significance of different radiologieal examinations in the di-agnosis of the prostate carcinoma through studying their radiological misdiagnosis rate. Methods By searching for patients having radiological examination results in the database of prostate carcinoma in Tianjin,got the patients whose examination results were different from prostate carcinoma. Analyzed the misdiagnosis rate of each kind of imaging diagnosis using x2-test retrospectively. Results In all patients searched, the misdiagnosis rate of transabdominal ultrasonography, transrectal uhrasonography (TRUS), CT , MRI was 45.1%, 10.1%, 34.5% and 7.5% respectively. Statistical analysis showed that the misdiagnosis rate of MRI was the lowest, then TRUS, and CT. Transabdominal ultrasonography had the highest misdiagnosis rate. There was not significant difference between MRI and TRUS. Conclusions As an efficient and important screening method, transabdominal ultrasonography still need to get a higher definite diagnosis rate. TRUS don't have obvious advantages over pelvis MRI in the diagnosis of prostate carcinoma except its usefulness in the biopsy of prostate. Pelvis MRI is still the most important imaging diagnosis of prostate carcinoma and should be first choice because of its noninvasive intervention, convenience and lowest misdiagnosis rate.