Urinary tract infection (UTI) is an infection of the urinary tract that is caused by pathogenic microorganisms that invade the urinary system, multiply in the urine, and invade the mucosa or tissues of the urinary tract causing an inflammatory response. There are upper urinary tract and lower urinary tract infections. The former refers to pyelonephritis, while the latter refers to cystitis and urethritis. Upper urinary tract infections are more dangerous, with the highest incidence in infants and young children. Repeated infections can lead to kidney scarring and, in severe cases, secondary hypertension and chronic renal failure. It varies with age and site of urinary sensation and has three main forms of presentation: pyelonephritis, cystitis and asymptomatic bacteriuria. 1, pyelonephritis infants and young children account for the majority of the symptoms of systemic infection poisoning as the main manifestation, often with fever of 38.5 ℃ or more, high fever may have convulsions or chills, along with general malaise, atrophy, pallor, vomiting, nausea, light diarrhea. Older children report hypochondriacal or lumbar pain and percussion pain in the kidney area. Newborns show symptoms such as sepsis, with weight loss, feeding difficulties, jaundice, agitation, fever or temperature not rising; 2. Cystitis mostly in older girls, with symptoms of frequent urination, urgency, difficulty urinating, incomplete urination, lower abdominal discomfort, pain in the suprapubic area, incontinence, sometimes foul-smelling urine, and eczema of the vulva. Cystitis usually does not cause fever; 3. Asymptomatic bacteriuria asymptomatic bacteriuria refers to positive urine cultures in children without any clinical symptoms of infection. It is almost exclusively in girls, but may develop into a symptomatic urinary tract infection if left untreated. Treatment: 1. bed rest during the acute period, drink more water, easy to digest diet containing sufficient calories and proteins; 2. bacterial urinary sensation according to the localization of urinary sensation diagnosis and pathogenic selection of drugs; 3. upper urinary tract infections use drugs with high blood and kidney concentration, lower urinary tract infections use drugs with high urinary concentration; 4. according to the examination of the pathogenic bacteria and their drug sensitivity test selection of drugs; 5. as far as possible with low toxicity drugs; 6. infants and children should be taken Active and effective treatment, such as those with vomiting and atrophy, intravenous medication is recommended. Cephalosporin antibiotics, especially the second and third generation cephalosporins, have a better effect and are generally administered for 5 to 7 days. For fungal-induced urinary tract infections available antifungal drugs; 7, the course of treatment: acute initial upper urinary tract infection by effective antibacterial therapy, more than 2 to 3 days fever gradually decline, urinary routine rapidly return to normal, the conventional course of treatment for 2 weeks. For those who do not recover well from treatment should be based on urine culture and drug sensitivity test timely replacement of antibiotics, the course of treatment takes 4 to 6 weeks. After the first urinary sensation is cured, the middle urine culture and colony count should be followed up for at least 1 year in the 1st, 2nd, 3rd, 6th and 12th months.