Abstract: Effective school Administrative Management is crucial for creating an environment where students and teachers thrive, ensuring quality education and fostering a culture of continuous improvement towards achieving core competencies, thus laying the foundation for learners’ future success. Despite several studies highlighting administrative challenges in Kenya’s education sector, barriers such as inadequate instructional resources management, and resource mobilization, continue to hinder the effective achievement Core competencies in the competency-based curriculum. This study aimed at establishing the influence of instructional resource management on junior school learners’ achievement of core competencies in the CBE in Laikipia County, Kenya. The Contingency Theory developed by Fiedler, Paul Lawrence and Jay Lorsch and the Situated Learning Theory by Jean Lave and Etienne Wenger guided the study. The study utilized descriptive survey design. A target population of 23067 from 242 junior schools comprising 242 headteachers, 21,425 junior school learners, 745 class representatives, 408 junior school teachers and 5 sub-county directors was used in the study. A sample size of 302 respondents comprising 88 junior school teachers, 51 headteachers and 160 junior school class representatives was proportionately and randomly sampled, while 3 sub-county directors was purposively sampled and used as respondents in the study. Questionnaires for headteachers, junior school class representatives and junior school teachers was used to collect data. Interview schedules was utilized to collect data from the Sub-County Directors. Quantitative data was analyzed using regression analysis while Qualitative data obtained from the interview schedule was analyzed descriptively and reported thematically in line with the research objectives. The findings of the study found out that Junior school instructional resource management influences the achievement of CBE core competencies in Laikipia County, Kenya. The null hypothesis was tested at 0.05 significance level. Regression analysis on influence of instructional resources on the achievement of CBC core competencies gave p value of 0.023 which was less than the critical value 0.05 denoting a statistical significance influence of instructional resources on the achievement of CBC core competencies. The study recommended that Government should equip all schools with enough, quality and relevant instructional resources and ensure their effective management for efficient achievement of learners’ core competencies in Junior schools. The study may be useful to stakeholders such as Ministry of Education and KICD in developing appropriate instructional materials and supply of relevant and sufficient instructional materials. 

Keywords: Competency Based Education, Instructional Resources, CBE Core Competencies, Junior Schools, Administrative Management