Objective: With a positive self concept, asthmatic schoolchildren are likely to accomplish self-management behaviors. The purpose of this study was, therefore, to investigate the self concept of school age children with and without asthma, and probe related factors. Materials and Methods: The subjects, 150 fourth to sixth graders of whom 50 were asthmatic and 100 were healthy, were purposively selected from a pediatric allergy outpatient clinic in a medical center in northern Taiwan. The research tools included a structured questionnaire, the ”Self Concept Scale” and the ”Parenting Style Scale”. Data were analyzed by descriptive and inferential statistics using SPSS for Windows/PC 10.0 software and StatXact-5 statistical software. Results: There was a significant difference between the self concept of asthmatic and healthy schoolchildren. Asthmatic children's overall self concept (p＜0.01), self concept family subscale (p＜0.05), and self concept physical subscale (p＜0.001) were lower than those of healthy children. Asthmatic children's limits in physical education class were significantly correlated with overall self concept, whereas the overall self concept was highest for children with full class attendance (p＜0.05) and no shortness of breath after exercise (p＜0.01). After modifying for the group effect, the parenting style and overall self concept were positively correlated (p＜0.001). Conclusions: These research results can serve as guidelines for medical care professionals, parents, and teachers, in caring for and teaching asthmatic and healthy schoolchild.