Extracorporeal shock wave lithotripsy is a proven method of treating urinary stones. It is highly recommended by medical practitioners and accepted by patients. It is recognized by the society. However, many stones are not successfully or completely broken at one time, why is this? In my clinical treatment and practice, I have both gained experience and learned lessons. The reasons for this are as follows: 1. Obesity Because obese patients have more fat, the distance from the stone to the body surface is farther, and the shock wave energy attenuation is too large. 2, stone site Ureteral middle and lower stones, the distance from the body surface is the farthest, and because of intestinal feces, gas and other interference. The shock wave can only be incident through the abdominal wall, resulting in energy attenuation; for stones in the middle and upper pole of the left kidney, as they are closer to the heart, low energy lithotripsy should be used as much as possible; for stones in multiple sites, lithotripsy must be divided according to the specific situation. 3. Medical history Ureteral stones stay too long (>6 weeks). The stone stays in the ureter for a long time and is located in three narrow areas of the ureter: (1) at the junction of the renal pelvis and ureter, (2) at the iliac vessels, and (3) at the bladder wall, resulting in edema of the wall around the stone, thinning of the lumen, and adhesion of the stone to the wall. The ureter, as a lithotripsy bed, loses tension and the shock wave energy is attenuated. 4.Stone composition Urological stones are dense and hard, and single component is rare. Most of them are mixed type of stones with one component. For example, calcium oxalate monohydrate, calcium oxalate dihydrate, etc., and cystine stones contain a large amount of organic matter, with strong bonding between crystals and no surrounding radiating laminar structure, which can easily prevent stone cleavage, etc. 5.Stone volume The stone volume is large and needs to be broken in stages, which is conducive to the smooth passage of the stone fragments through the ureter. 6.Old age and frailty For old age and frailty or children, low energy lithotripsy should be used as much as possible to ensure safety and efficacy. 7.Other patients with poor foundation or other chronic diseases need to be lithotripsed in different stages.