[영문]AB Background: Previous research has documented an underuse of long-term control medications among children with asthma, in nonadherence with national guidelines on asthma care. Objectives: To determine if factors related to access and quality of asthma care are associated with underuse of long-term control medication among children with asthma. Research Design: A parent-report cross-sectional survey conducted in 26 randomly selected New York City public elementary schools. Subjects: Five thousand two hundred fifty children, of whom 912 had asthma. Results: Twenty-nine percent of children with asthma reported using a long-term control medication. Among children with persistent asthma, defined as having one or more sleep disturbances due to asthma per week, 59.0% reported using a long-term control medication. After adjusting for demographic factors, children who had an asthma plan, had visited a doctor in the previous 6 months for nonurgent asthma care, or were enrolled in an asthma education program were more likely to use long-term control medication (odds ratios: 6.00, 4.11, 2.88, respectively). Children of Spanish-speaking parents, African American children, and children with no health insurance were the least likely to use long-term control medication (odds ratios: 0.51, 0.49, 0.20, respectively). Children who reported recommended components of asthma care were the most likely to use their medication with appropriate frequency. Conclusions: Children who reported markers of high quality, personalized medical care, were more likely to use long-term control medication. These findings illustrate that components of the medical care received, and not only the demographic characteristics of the patient, are key factors in understanding the underuse of long-term control medication in urban children with asthma