The findings are based on a larger study on systematically comparing leadership development and practice in seven differentially performing education systems (Malaysia, Australia, Hong Kong, England, Indonesia, Russia, and Singapore) (Harris et al.). The contextual background of principalship training in Hong Kong was the Principals’ Continuing Professional Development Framework introduced since 2002 (Education Department, 2002). Under this Framework, all existing and newly appointed principals have been required to undergo continuous professional development or prior certification (Education Bureau, 2010). Based on 20 interviews with principals, key staff and teachers of three secondary schools in three different bandings. One of key themes identified in the data is the roles of the school principal as a change agent. This key finding is compatible with findings that highlighted the prominent role of the principal as a key change agent for the successful implementation of school-based management, both in Hong Kong (e.g. Cheng, 1992; Ma, 1993; Ko & Walker, 2014; Ko, Cheng & Lee, 2016) and in schools worldwide (e.g. Hallinger, 1992; Hopkins & Reynolds, 2001; Marks & Printy, 2003; Wohlstetter et al., 2008).More specifically, the roles of school principals are discussed in relation to the different conceptualisations and charaterisations of principalship in transactional, instructional, transformational, and distributed leadership theories.