This study aimed to investigate the effectiveness of using the Wittrock model in the acquiring geometric concepts and systemic thinking among ninth graders. It used a semi experimental method, that was applied to a sample of (52) students distributed among two divisions of the grade ninth students, randomly selected from one of the schools affiliated to the Directorate of Education in the Governorate of South Batinah. The students were divided into two groups: an experimental group consisting of (26) students who studied the unit of circle geometry using the Wittrock model, and a control group consisting of (26) students who studied the same unit by a traditional method. To achieve the research objectives, the researcher designed a teacher's guidebook for unit five which is about " circle geometry " based on Wittrock model. Two tools were applied for this study, which are a test designed by the researcher to examine the students' acquisition of geometry concepts and a test to examine their systemic thinking. The semantic validity and reliability of the study tools have been extracted in the appropriate ways and they were found to be acceptable for the study demands. The results of this study revealed differences at the level of significance (α = 0.05) between students mean scores in the experimental and control groups in the post- test in both geometric concepts test and systemic thinking test for the experimental group. Based on the results, the researcher recommended the necessity of applying Wittrock model in teaching Mathematics topics as the study has shown positive impacts in acquiring geometric concepts and systemic thinking among female students.