This paper studies the relationship between principals’ reward power and their conflict management styles. The five conflict management styles that we use in this study are based on Thomas-Kilmann Conflict Mode Instrument and include accommodating, avoiding, collaborating, competing, and compromising styles. This study can be classified as a regression analysis and is a descriptive study. Our statistical society for this research included all principals of high schools located in the city of Birjand. The results indicated that there was a significant relationship between principal’s reward power and accommodating conflict management style. The results also revealed that there was no significant relationship between principals’ reward power and the other four conflict management styles.