 Background: Urolithiasis in children is a painful and costly disease that may also have detrimental long-term effects on kidney function. Although urolithiasis is rarely found in the pediatric population, several studies indicated that the incidence and inpatient hospitalization rates were sharply increased. The incidence of nephrolithiasis for children aged 18 years in South Carolina was 18.5 per 100,000 children in 2007, much higher than 7.9 per 100,000 in 1996. Data from Iceland revealed an incidence of 5.6 per 100,000 children aged 0 to 18 years on the basis of 26 new diagnoses of renal stone during a 6-year period among a national population of approximately 78,000 children. The composition analysis of stone in children revealed that the calcium stone was the most common one, accounted for 72 to 88, and the uric acid stone accounted for 2 to 3 while the infective stone included ammonium acid urate and magnesium ammonium phosphate was rare. 