The objective of this study was to evaluate the prevalence and relative risk of off-label prescription of antidepressants in Chinese pediatric outpatients according to China Food and Drug Administration (C-FDA) and USFDA regulations. Medical records of 18 459 pediatric outpatients were identified between 2013 and 2015. Patient characteristics, prevalence of off-label antidepressant prescriptions, and relative risk factors associated with off-label prescribing were analyzed. The results indicate that patients aged from 12 to 17 years account for 88.1% of antidepressant prescriptions, with the most commonly prescribed being sertraline (41.4%). In total, 90.0 and 84.1% of antidepressant prescriptions were off-labeled according to C-FDA and USFDA, respectively, and off-label indications was the most frequent type in this study. Depression was the most common indication for antidepressant treatment, followed by bipolar disorder and schizophrenia. Patients aged 12-17 years diagnosed with bipolar affective disorder have a high risk of off-label antidepressant prescription according to C-FDA regulations. Patients diagnosed with obsessive-compulsive disorder have a low risk of off-label antidepressant prescription according to both regulations. Therefore, future studies are recommended to collect evidence to safeguard appropriate prescribing of off-label antidepressants among pediatric patients.