This study attempted to track down the changing trajectory of burnout of 315 eighth graders for three consecutive semesters, and to explore the influences of individual (i.e., perfectionistic tendencies and achievement goals) as well as environmental factors (i.e., teacher autonomy support vs. psychological control) on academic burnout during the above period of time. Hierarchical linear growth models were employed for analyzing the data. Results indicated that junior high school students experienced higher levels of burnout as they proceeded to higher grades. Regarding the determinants of academic burnout, maladaptive perfectionism, performance-avoidance goals, and teachers' psychological control exerted significantly positive influences on students' burnout, whereas adaptive perfectionism, mastery-approach goals and performance-approach goals, together with autonomy support provided by teachers negatively affected burnout. Implications for counseling practices and future research were discussed.