ObjectiveThere has been growing evidence of comorbidity between problematic internet game use and internalizing and externalizing problems in young people. However, little is known about the directionality and gender differences in these longitudinal relations at the symptoms level in the framework of network theory among youth. This study estimated the longitudinal relations between the symptoms of problematic internet game use, internalizing and externalizing problems, and the gender differences of these relations in Chinese youth using cross-lagged panel network modeling (CLPN). MethodsA sample of 1269 Chinese youth (M age = 10.35 years) participated in this study semi-annually at two time points. CLPN analysis was used to calculate the network model of problematic internet game use and internalizing and externalizing problems to explore bridge symptoms and find transmission pathways between problematic internet game use and internalizing and externalizing problems. ResultsThe CLPN revealed significant gender differences. For boys, depressed mood, which leads to relationships turning sour in order to play online games, bridges the relations between internalizing symptoms and problematic internet game use. For girls, irritability is the central predictive symptom, causing a range of problems related to problematic internet game use, which can, in turn, lead to fights or feelings of worthlessness. However, the effect sizes for the pathways between problematic internet game use and internalizing/externalizing problems were relatively weak, and the comorbidity between their relations should not be over-interpreted. ConclusionsThe current findings provide new evidence for understanding the directional relationship between the central characteristics of problematic internet game use and internalizing and externalizing problems in boys and girls. Gender-specific interventions targeting the central symptoms of internalizing and externalizing problems and problematic internet game use can help mitigate the vicious cycle of comorbidity among adolescents.