Purpose: This study aims to investigate the factors of suicidal ideation and emotional characteristics by health risk behaviors among adolescents using the data from the 16th Korea Youth Risk Behavior Survey(2020). Methods: A total of 57,925 students were analyzed using the STATA 12.0(StataCorp, College Station, Texas) program. We analyzed the relationship between health risk behaviors and suicidal ideation and emotional characteristics using logistic regression analysis. Results: According to logistic regression analysis, suicidal ideation was associated with gender, school grade, economical status, residence type, smoking, drinking, drug, happiness, despair, stress, loneliness, and generalized anxiety disorder. Conclusions: Among the emotional factors, the effects of loneliness and generalized anxiety disorder on adolescent suicidal thoughts were identified and analyzed. So, it is necessary to come up with various measures to lower negative emotions and improve hope.