A striated mass in the urethra is one of the symptoms of urethral diverticulum, a cystic cavity around the urethra that communicates with the urethra. It can be congenital or acquired. Congenital urethral diverticulum is more common in women, mostly single, located between the urethra and vagina; in men, it is located on the ventral side of the urethra at the scrotal junction of the penis. Diverticula vary in size and neck width, causing different degrees of urinary tract obstruction and symptoms. Congenital urethral diverticulum, the wall is covered with epithelial cells, and there are smooth muscle fibers in the wall of the diverticulum. Acquired diverticulum wall is mechanized fibrous tissue. Congenital urethral diverticula are mostly in the penis and bulbous urethra, located in the ventral side of the urethra. Acquired ones can occur anywhere in the urethra. The size of the diverticular opening varies, with the congenital diverticula having a wide opening and the acquired ones generally having a smaller opening. At the distal end of the margin of the diverticular opening, some have valves present. Some believe that the flap is caused by poor urethral connection, but it is also possible that urine enters the diverticulum during urination, and the pressure within the diverticulum presses the anterior lip of the diverticulum into the urethra, forming a flap that affects diverticular drainage. The diverticulum can develop secondary infection, stones, and a urinary fistula can form when it is punctured. The tests that need to be done for a striated mass in the urethra caused by urethral diverticulum are routine urinalysis, urine bacterial culture, imaging, cystography, and other tests. When the diverticulum is combined with an infection, routine urinalysis may show red and white blood cells, and urine culture may show pathogenic bacteria. Diverticula can be seen by urethrography, and voiding cystourethrography should be performed for posterior urethral diverticula. Urethroscopy, also helpful in diagnosis, but care should be taken to avoid penetrating the diverticulum. Other tests, such as urethra, cystography, followed by CT, MRI examination can also be clear.