This research aimed to explore the effects of parent-child relationships, teacher-student relationships, educational expectations, learning situations, and academic achievement on academic performance. The sample was comprised of 1402 junior high school students, and was drawn from the “Taiwan panel study of children and youth”. After analysis, the major conclusions of the study were as follows: 1. parent-child relationships have a negative influence on academic achievement; 2. teacher-student relationships have a negative influence on academic achievement; 3. teacher-student relationships have a positive influence on learning situations; 4. educational expectations have a positive influence on learning situations; 5. learning situations have a positive influence on academic achievement; 6. learning situations have a significant mediating effect on the relationships among parent-child relationships, teacher-student relationships, and educational expectations. Finally, a number of suggestions based on the findings are offered as a reference for school administrators.