The normal solid structure of the kidney consists of two layers connected inside and outside, the outer layer is called the renal cortex and the inner layer is called the renal medulla. The inner layer is called the renal cortex and the inner layer is called the medulla. In medullary sponge kidney, the urinary ducts located in the medulla of the kidney are dilated in the form of small sacs and look like sponges, hence the name. Medullary sponge kidney is a rare kidney disease that was only recognized in the 1930s. The cause of its pathogenesis is not yet understood and may be related to certain genetic alterations. Patients with medullary sponge kidney often present with renal calculi, distal tubular acidosis and hypocitraturia. Some patients have a combination of polycystic kidney, horseshoe kidney, nephroblastoma and hyperparathyroidism. Patients may develop secondary urinary tract infections and hematuria, and some patients develop renal function impairment or even uremia. Diagnosis mainly relies on imaging examinations. Previous intravenous pyelogram is most commonly used, and nowadays CT urography is mostly used, as well as abdominal plain film and sometimes endoscopy such as ureteral flexible microscopy to confirm the diagnosis. Patients should pay attention to regulating their diet and drink more water on a daily basis. Potassium citrate and celebrex diuretics are helpful in preventing the formation of new stones. Surgery may be considered in cases of recurrent stone discharge, urinary tract infection, hematuria, or significant back discomfort.