Abstract: “The purpose of this study is to identify smartphone addiction that were likely to become risk factor for suicidal ideation and to define the mediating effects of adolescents' selfcontrol. This study is attention to the effect of Smartphone addiction as a new risk factor. Family and school problems on previous studies for the adolescent suicide that used to be focused are control variable. In order to accomplish this purpose, a total of 1,601 who are middle and high school students in Seoul and Gyeonggi province, South Korea were utilized. The data were analyzed by frequency analysis, and the multiple regression model analysis with SPSS 21.0. The main results of this study are as follows. First, about four out of ten (40.4%) of adolescents have experienced the thought of committing suicide for the past year. Second, Smartphone addiction risk, is 24.5 percent of all respondents. This means about 2.5 out of every 10 from the use of smartphone addiction have a severe risk side effects like”

Keywords: Korean adolescents, Smartphone Addiction, Self-control, Suicidal Ideation