China has been promoting student-centered education under the current curriculum reform. However, teachers in rural schools continue to exercise tight control of the classroom, with lecturing taking up most of the class time. Drawing on ethnographic observation and interviews in a rural elementary school, this study analyzes the rationale of rural teachers in strategizing teaching methods. It has found that teachers' pedagogical choices are heavily constrained by both the centralized curriculum and schedule and the social context of rural-urban disparities. Together these constraints create a dilemma of time that significantly limits the room for teachers to experiment with student-centered methods. (Contains 1 table.)