A study on antibiotic abuse and inappropriate use was conducted in 750 children under five years old with acute respiratory infection (ARI) in Tongxian County, Beijing, based on WHO's ARI Standard Case Management for Young Children, who sought medical care in clinics at county, township, and village levels provided by 100 physicians. Results showed 96.9% of them were defined as antibiotic abuse and 62.9% as inappropriate use. Factors that contributed to antibiotic abuse and inappropriate use were length of medical practice of physicians the ill children consulted, their education level, scores of their knowledge and attitude, their diagnostic skills, purposes for antibiotic use, whether or not to enjoy free medical care by employees' dependents, ill children's degree of fever and self-prescription by parents, and so on.