Patient description: The patient is a 55 year old man visiting his primary care physician for lower urinary tract symptoms including frequency, urgency, weak stream, incomplete emptying and intermittent flow for the past 9 months. Further evaluation revealed: IPSS score : 15 Post-void residual: 70 mL Prostate volume (TRUS): 60 mL Prostate-specific antigen (PSA) level: 3.2 ng/mL 10 mL/sec of maximum flow rate when urine volume was 130 mL He is otherwise healthy only using Vit D 1000 units daily. His recent blood chemistry (3 days ago) was normal: Hgb: 13.5 g/dl WBC: 135000 /mm3 Plt: 350000 /ml PT: 11 second PTT: 35 second INR: 0.9 Creatinine: 0.5 mg/dl BUN: 10 mg/dl U/A: Color: yellow Appearance: cloudy PH: 5.3 Specific gravity: 1.010 Glc: 100 Nitrite: negative Ketone: none Leukocyte esterase: negative RBC: negative WBC: 2 WBCs/hpf U/C: negative

Clinical trial eligibility criteria: eligible ages (years): 50.0-999.0,  Lower Urinary Tract Symptom Benign Prostatic Hyperplasia (BPH) A. Men ≥ 50 years of age. Healthy patients or volunteers without diagnosis of Lower urinary tract symptoms (LUTS) / Benign prostatic hyperplasia (BPH) will not be included. B. Patients diagnosed of LUTS / BPH，International Prostate Symptom Score > 12 with mild to severe symptom of LUTS. C. Prostate volume > 50 mL. D. Urinary flow rate <15 mL / sec. E. Ineffectiveness after 6 months of previous medical treatment, or the side effects are too difficult to tolerate  If patients meet any of the following they may not be entered into the study: A. Major pelvic disease, or other malignancies. B. Prostate specific antigen of serum > 10 ng/mL, malignant tumor not yet rule out (prostate specific antigen PSA>10 ng/mL). C. Had Prostate surgery. D. Chronic bacterial prostatitis. E. Renal dysfunction or bladder diverticulum stones caused by prostate disease obstruction. F. Main organs (heart, lung, liver, kidney) dysfunction who are not eligible for clinical trials under physicians' consideration. G. White Blood Cell< 2000 or Severe thrombocytopenia（Platelet count <50,000/μL)，or blood coagulation abnormalities uncorrectable . H. Unable to follow-up by MRI 3 times. I. Unable to follow-up by ultrasound or CT scan. J. Unwilling to sign a written informed consent form. K. Allergic to Iodine or other injections. L. Acute bacterial prostatitis. M. Patients with active urinary tract infections or recurrent urinary tract infections (>2/years), prostatitis, or interstitial cystitis. N. Cases of biopsy proven prostate, bladder, or urethral cancer. O. Patients with glomerular filtration rates less than 40 who are not already on dialysis. P. Patients with bilateral internal iliac arterial occlusion. Q. Patients with causes of bladder obstruction not due to BPH (eg urethral stricture, bladder neck contraction, etc). R. Patients with neurogenic or bladder atonia. S. Patients where embolization is not possible distal to collateral vessels feeding non-prostatic tissue. T. Patients with major neurologic illnesses which could have symptoms that may be similar to or confused for BPH (eg multiple sclerosis, Shy-Drager syndrome, spinal cord injury, etc.). U. Patients with urethral stents. V. Other than hemorrhoidectomy or pelvic irradiation, patients who have undergone prior rectal surgery. W. Patients who have started or changed their dosage of alpha blockers or 5-alpha reductase inhibitors in the month prior to prostatic artery embolization. X. Allergic to pharmaceutical excipients related to Microspheres