目的：探讨前列腺内动脉血流阻力指数（ＲＩ）在鉴别诊断前列腺癌与前列腺增生症中意义。方法：应用彩色多普勒超声检测前列腺增生患者、前列腺癌患者及正常成人的前列腺内的动脉血流阻力指数，与其病理结果相比较。结果：前列腺内动脉血流均为低速特征，前列腺癌患者的前列腺内动脉血流阻力指数显著低于前列腺增生症患者和正常人前列腺内的动脉阻力指数，而前列腺增生症患者的前列腺内动脉阻力指数与正常人前列腺内的动脉阻力指数差异不显著。ＲＩ＜０．４５则可作为鉴别诊断前列腺癌和前列腺增生症 Objective: To explore the significance of intra-prostatic artery blood flow resistance index (RI) in the differential diagnosis of prostate cancer and benign prostatic hyperplasia. Methods: Color Doppler ultrasound was used to detect the arterial blood flow resistance index in patients with benign prostatic hyperplasia, prostate cancer and normal adults, and compared with their pathological results. RESULTS: Prostatic arterial blood flow was characterized by low velocity. Prostate artery artery arterial resistance index was significantly lower in prostate cancer patients than in benign prostatic hyperplasia patients and normal subjects. Intraprostatic arterial resistance was observed in patients with benign prostatic hyperplasia. There is no significant difference in the index of resistance between the index and normal human arteries. RI < 0.45 can be used as a differential diagnosis for prostate cancer and benign prostatic hyperplasia