This study intends to explore the change in students’ question-answering behavior in online English classrooms and factors contributing to the change. The results indicate that students are more willing to answer questions voluntarily in online classrooms. Changes in teachers’ questioning behavior, students’ reduced sense of pressure and students’ preparation caused by transformation in teaching media are the direct and significant factors for students’ improved willingness to answer questions in online classrooms; while changes in interactive environment is an indirect factor for such an improvement.