The purpose of this study was to identify teachers’ perspectives on their principals and the experiences of the dark side of school principals' leadership. Data were collected through survey and from in-depth interview conducted with teachers during one and half year. The major findings were as following: (a) most teachers were unsatisfied with the present principals and have experienced the negative principals. And the majority of the teachers responded personality and behavior as negative principals’ leadership. (b) the dark side of principals’ leadership were unethical, immoral, inconsistency, ignoring, distrust, partiality/unfair, unreasonable, nitpicking, criticism, and forcing (behaviors)/aggressive, excitable, cautious, reserved, leisurely, skeptical, dutiful, insensitive, and stubborn (characteristics)/ignorant and inexperienced (skills)/stereotyped (knowledge). (c) the dark side of leadership was harmful to teachers' psychological/emotional/physical health as well as school culture/climate and activities/outcomes. At the end of the paper, it is discussed the directions and challenges of the research for the school principals' leadership.