This Study was conducted to examine the relatonship between insufficient sleep and internet usage among middle school students. This study is a secondary analysis of the data collected via the 11th Korea Youth Risk Behavior Web-based Survey Questionnaire(2015) was conducted. The subjects of this were 34,299 middle school students who took the corresponding survey. Data analysis was complex stratified sample data were used with SPSS 22.0 program. The results showed that the internet usage during the weekday had a statistically significant effect on the sleep duration. Those who sleep over seven and under eight hours during the weekday were 1.18 times(p<.001) risk of using the internet for more than 3hours than those who sleep over 8hours during the weekday. Also, the value was 1.38 times(p<.001) for those who sleep over six and under seven hours, 1.84 times(p<.001) for those who sleep over five and under six hours, and 2.97 times(p<.001) those who sleep under 5hours. In conclusion, it was found that middle school students had the highest risk of using the internet for more than 3hours during weekday when sleep duration was less than 5hours. Therefore, proper management of the internet usage of adolescent is needed.