This study aims to examine the effect of sources of power used by school principals on preschool teachers' occupational sense of belonging level. Correlational survey model was used in this quantitative study. The participants of the research consisted of 396 volunteering preschool teachers currently working in 53 different cities in Turkey. 'Organizational Sources of Power Scale' and 'Occupational Sense of Belonging Scale' were used as data collection tools. Data were analysed in software package program. Pearson correlation analysis was performed to determine the relationships between sources of power and occupational sense of belonging levels. It was determined whether sources of power were predictors of occupational sense of belonging level through regression analysis. The results of the study show that school principals use legitimate power most frequently and preschool teachers have a high level of professional belonging. There is a significant and positive relationship between referent power, expert power, reward power and legitimate power used by school principals and preschool teachers' occupational sense of belonging levels. There is a significant and negative relationship between the coercive power used by school principals and preschool teachers' occupational sense of belonging levels. Referent power and reward power, which are sources of power used by school principals, are significant predictors of preschool teachers' occupational sense of belonging levels. The findings were discussed and recommendations were presented in relation to the relevant literature.