(5) the choice of drugs with strong antibacterial ability, broad antibacterial spectrum, preferably with a strong bactericidal agent, and not easy to make the bacteria produce drug-resistant strains; (6) if there is no drug sensitivity test results, for upper urinary tract infection or acute pyelonephritis recommended to use more than two generations of cephalosporins and their potent stabilizers, ampicillin/rod acid complex, amoxicillin clavulanic acid. 2.Treatment of upper urinary tract infection or acute pyelonephritis: the course of treatment is 7～14d. 1）≤3 months old infant: the whole course of intravenous sensitive antibiotic treatment; 2）>3 months old: if the child has symptoms such as poisoning, dehydration or cannot tolerate oral antibiotic treatment, can first use intravenous sensitive antibiotic treatment for 2～4 d and then switch to oral sensitive antibiotic treatment, the total course of treatment is 10～14d; 3）If antibiotic treatment 48 h If the expected therapeutic effect is not achieved after 48 h of antibiotic treatment, urine should be re-taken for bacteriological examination of urine culture. (4) If the imaging-related examination has not been completed, oral treatment with a small dose (1/3 to 1/4 of the treatment amount) of antibiotics should be continued after the full course of antibiotic treatment until the imaging examination shows no vesicoureteral reflux and other urinary tract abnormalities. 2, treatment of lower urinary tract infection or cystitis: 1) Take oral antibiotics for 7-14 d (standard course). 2) Take antibiotics for 2-4 d (short course), short course is recommended. 3) The effect of treatment needs to be evaluated after 48 h of antibiotic treatment, including clinical symptoms and urinalysis indexes. If the expected therapeutic effect is not achieved after 48 h of antibiotic treatment, urine needs to be retrieved for urine culture bacteriological examination.