Purpose: Quality of education in multi-grade classrooms is important in the education system, neglect of which is associated with the weakness of the education model and related factors. Methodology: The present study was conducted to validate a model for the quality of education in multi-grade classrooms in primary schools as exploratory research. In qualitative study, thematic analysis was used by an inductive approach, and in quantitative study, descriptive survey was used. Given the components, an 81-item questionnaire was provided. To validate the questionnaire, convergent validity, content validity and construct validity were used. The statistical population of the research included teachers, principals and educational leaders of multi-grade classrooms in all the cities of North Khorasan Province, including 1203 multi-grade classrooms. By Cochran's formula, 349 people were selected as the research sample. The structural model of the research was fitted and the path coefficients of the research model were analyzed by the bootstrap method (resampling and sequential sampling) and the Student's t-test statistic. Findings: According to the results, 0.823% of the changes in the quality of multi-grade classrooms have been predicted by the sub-components of teachers' professional competence and characteristics, macro policies, the state of schools, family model and themes related to the students. Conclusion: All questions were confirmed due to a factor load above 0.5, and the model had a good fit.
