Adolescence is the peak period for the occurrence of mental health issues, particularly in the stage of junior high school. Depressive symptoms are among the most frequently experienced psychological problems. However, little is known about the symptom-level interaction features of depressive symptoms and the roles of different symptoms across the junior high school stage. To address these gaps, this study conducted a three-year longitudinal study that recruited 1301 Chinese junior high school adolescents (48.2% females; mean age = 12.46 ± 0.62, ranging from 11 to 14 in the first year). The Center for Epidemiological Studies Depression Scale was used to assess depressive symptoms. The regularized partial correlation network and the cross-lagged panel network models were used to explore the symptom-level interaction pattern. In regularized partial correlation networks, “I felt depressed” was a stable central symptom throughout the junior high school stage. Besides, “I felt lonely” and “I felt that people disliked me” were the other central symptoms in grade 7 and grade 8, and “I felt everything I did was an effort” played a central role in grade 9. Within cross-lagged panel networks, “I felt that people disliked me” and “I felt hopeless about the future” had important effects on predicting other depressive symptoms from grade 7 to 8 and from grade 8 to 9. By investigating the longitudinal interaction patterns of depressive symptoms among junior high school adolescents, the current study identifies core symptoms that could be potential prevention or intervention targets and provides a novel insight for understanding depressive symptoms during adolescence in depth.