The purpose of this study was to explore the influence of system schema teaching strategy on improving the high school students' conceptions of force and correcting their misconceptions of force by empirical data. The subjects consisted of two classes of 11th graders. Researcher's class consisting of 48 students was the experiment group that received system schema instruction. Another teacher's class consisting of 49 students, the control group, received traditional expository instruction. The results of the study were as follows: (1) The lower the students' conceptual understanding on force was, the more the system schema teaching strategy improved their conceptions of force; (2) The system schema instruction can correct more misconceptions of an additional force than the traditional expository instruction.