In the modern information and knowledge society, every citizen stands to benefit from advanced ICT and smart techniques. However, in proportion to such benefits, many side effects also come to us. The typical side effects are copyright infringement, hacking, cyber bullying, internet addiction, etc. Internet addiction can occur at all levels, can also cause serious social problems unless the appropriate prevention and treatment programs are provided at national level. The purpose of this paper is to investigate correlation between internet addiction and school age groups. To achieve this purpose, extensive and national survey works of National Information Society Agency of Korea (NIA) are analyzed. Based on results of thorough statistical analysis, it is concluded that there is a meaningful correlation between internet addiction and school age groups.