The efficacy of extracorporeal shock wave lithotripsy (ESWL) is related to the size of the stone, but also to its location, chemical composition, and anatomical abnormalities. (1) Size of the stone: the larger the stone, the more likely it is to require retreatment. ESWL should be preferred for kidney stones less than 20 mm in diameter; stones larger than 20 mm in diameter and deerstalker-shaped stones can be treated with percutaneous nephrolithotomy (PNL) or combined with ESWL . If ESWL is used alone, it is recommended to insert a double J tube before ESWL to prevent the formation of a “stone street” to block the ureter. (2) Location of stones: Pelvic stones are easily crushed, and stones in the middle and upper renal calyces are more effective than stones in the lower calyces. For those with an acute angle between the funnel of the lower calyx and the renal pelvis, a longer funnel length and a narrower funnel width, stone removal after ESWL is unfavorable. (3) Stone composition: magnesium ammonium phosphate and calcium oxalate dihydrate stones are easy to crush, uric acid stones can be combined with lithotripsy for ESWL, and calcium oxalate monohydrate and cystine stones are more difficult to crush. (4) Anatomical abnormalities: malformations of the renal collecting system such as horseshoe kidney, ectopic kidney and transplanted kidney stones can affect the discharge of stone fragments and can be treated with adjunctive lithotripsy. (5) Number of ESWL treatments and treatment interval: The recommended number of ESWL treatments should not exceed 3-5 (depending on the lithotripter used), otherwise, percutaneous nephrolithotomy should be chosen. There is no definite standard for the interval of treatment, but most scholars, by studying the time of repair after kidney injury, believe that an interval of 10~14 days is appropriate.