For many years, many scholars have studied the question of how urinary stones are formed, but no definitive answer has been found. This is because neither the physician nor the patient can say when the stone was formed, and it is difficult to find out why it was formed. The only information available to the physician is the symptoms described by the patient at the time of presentation, the reports of the tests performed on the patient, and the results of the analysis of the stone specimens obtained when the stones have already formed, so the physician can only indirectly analyze the cause of stone formation. The main factors related to the formation of urinary stones are the following: 1. local lesions of the kidney mainly include calcified plaques in the renal papillae, calcium salt deposits in the renal parenchyma, microstones formed by obstruction of the lymphatic vessels in the kidney, etc. 2, the supersaturated state of urine normal human urine are supersaturated, when the supersaturated state exceeds a certain limit and reaches supersaturation, there will be some tiny crystals, called daisy crystals. Later these daisy crystals slowly grow and gather together to form granules that adhere to the mucosa and epithelium. If these particles stay in the narrow part of the urinary tract and continue to increase in size, they become microstones, which continue to grow and become stones. 3.Inhibitors in urine Although the urine of normal people is oversaturated, but generally will not precipitate crystals, because there are inhibitors in the urine. The inhibitors in urine include various low molecule inhibitors and high molecule inhibitors, which can inhibit the precipitation of crystals and play a protective role. When there is a lack of inhibitors in the urine, the urine in a supersaturated state will precipitate crystals and then form stones. 4. The matrix in urine plays a role in the formation of stones and facilitates the formation of stones. 5.Promoters in urine The substances in urine that promote stone formation include crystals themselves, TH glycoprotein, bacteria, foreign bodies, etc.