Objectives: The purpose of this study was to examine health behavior and disease of children and adolescents. Method: Data was taken from the Korean National Health and Nutrition Examination Survey. The SPSS 12.0 program was used for statistical analysis of data collected. Results: For the past one year, 57% of study group had oral examinations, 43.9% of them were vaccinated against influenza, and 16.9% tried to control body weight. Many children and adolescents (37.7%) had diseases, and 16% were diagnosed chicken pox. Of the subjects who were over 10 years old 35.9% had low high density lipid. The difference of sickness status between children and adolescents was significant ($x^2$=8.376, P=.015). The differences between children and adolescents in subjective health status, oral examination, vaccination of influenza, subjective physical change, body weight change and weight control efforts in the past one year were significant. The differences between children and adolescents in diagnosis of sinusitis, pneumonia and low HDL were statistically significant. Conclusions: The children and adolescents have different characters in health perimeters and these factors should be considered in order to improve the health status of children and adolescents.