Purpose: To explore the mediating effect of school interest and maladaptive cognitions in the relationship between stress and Internet addiction. Design and Methods: A total of 2271 high school students were recruited from a Chinese high school. Serial mediation model was used. Results: School interest and maladaptive cognitions had 0.03 and 0.13 indirect effects in the association between stress and Internet addiction, and accounting for 7.9% and 34.2% of the total effect, respectively. The serial indirect effect of school interest and maladaptive cognition was 0.05, accounting for 13.2% of the total effect. Practice Implications: The present study highlights the need of reducing stress and increasing school interest among high school students to prevent and intervene the occurrence of Internet addiction.