This study investigated the effect of student-centered instruction in improving students graphical interpretation skills and conceptual understanding of kinematical motion in Bistu Gebre Michael Catholic general and preparatory school found in Bahir Dar town of Amhara National Regional State, Ethiopia. A total of 77 (39 female and 38 male) grade nine students were involved in the study. The design adopted in the study was non-randomized pre-test and post-test control group design. The instrument used in gathering data for the study was background survey, Graphical Interpretation Skill Test (GIST) and Motion Content Test (MCT). Chi-square ( 2) and t-test were used as statistical analysis. The internal reliability coefficient of the test was 0.73 using Kuder Richardson Formula-20 (KR-20). The result showed that studentcentered instruction was found to be more promising in improving students‟ graphical interpretation skill and conceptual understanding of kinematical motion.