SUMMARY Intestinal primary intestine-derived adenocarcinoma of the bladder substituted by the intestine is a very rare long-term complication after complete urethral reconstruction of the bladder. The probability of its occurrence is low. However, in recent years, it has been proved to be objective, but there is rare literature about its diagnosis and treatment methods. This article describes a case of cystectomy and Studer ileal conduit in Peking University Third Hospital due to bladder cancer. After 9 years, he was discovered with a primary intestinal-derived adenocarcinoma in the bladder substitutes by the intestine. A male patient, 64 years old, with persistent abdominal pain in the lower abdomen for two weeks. There was carrion-like material in the urine, no gross hematuria, no urinary frequency, urgency, dysuria, and no abnormalities in the examination. Urinary CT showed intestinal metaplasia in the bladder. There was 5.7 cm×2.4 cm×4.8 cm irregular tissue shadow, and ureteroscopy found, on the right side, the bladder tumor whose diameter was 4-5 cm. We performed open lumpectomy and repaired the bladder, and postoperative pathology showed middle-high differentiated adenocarcinoma. The patient recovered well after the surgery. This article reviewed the similar intestinal primary intestine-derived adenocarcinoma of the bladder substituted by the intestine and found that it had the highest incidence in the elderly male population. The pathogenetic factor was most closely related to the smoking. If the patients developed hematuria, carrion-like substances in the urine, and bladder irritation, the possibility of tumor development should be suspected. Then the patients should promptly take the tests, such as urine exfoliation cytology, urine FISH, urinary system B-ultrasound, cystoscopy, etc. The microscope was the most direct observation of the lesion site examination. If the pathological tumor occurred ,and then the tumor should be immediately removed, and a new urinary diversion was needed to avoid further progress of the tumor. And postoperative smoking was strictly prohibited, also the patients should strictly control their eating habits and regularly adhere to the follow-up at least 4 years or more, but the lifelong follow-up and review was a must. The mechanism of intestinal primary intestine-derived adenocarcinoma of the bladder substituted by the intestine is still unclear. Studies suggest that it may be related to N-nitroso compounds, smoking, and postoperative inflammatory reactions.