This study aimed to form school accreditation standards for cycle two in basic education schools in the Sultanate of Oman. The descriptive approach was used in this study through the analysis of some International, Arabian, and GCC accreditation standards, and the literature associated to school accreditation and assessment standards. The outcome of this approach was used in deriving the best educational practices that fit with educational environment in cycle two schools in Oman. To achieve the objectives of the study were prepared questionnaire consisted of (10) axis represented a list of criteria for accreditation of school. Each criterion consisted of a group of procedural indicators which enables inferring the level of achieving the criterion which amounted (78) procedural indicators. After checking the instrument's reliability and validity, it was conducted on a sample of ( 490) persons. Representing administrative supervisors, assessment of school performance supervisors, School headmasters and headmistresses and their assistants and senior teachers in the following regions: Muscat, Al-Batina North, Al-Dakilya, Al-Sharqia North, and Dofar. Including supervisors in the circuit of developing schools performance in the directorate- general for human resources development in the Ministry of Education. The study found out the following standards for assessing and accrediting cycle two schools: strategic planning, management of human and financial resources, school educational environment, community participation, the school building, safety and security procedures, school curriculum and methods of teaching used, methods of evaluating students of academic achievement and results, laboratories and learning resource centers, student services and School's activities, and the school improvement plan. The results of the study showed a high degree of agreeing of the sample study on the standards' list, and the overall mean for the list was ( 4.36). Many recommendations and suggestions have been introduced according to the results of the study.