Lesson Study has been the main collaborative action research approach for enhancing learning and teaching and promoting teacher professional development in Hong Kong in the past decade. Lesson Study innovation in Hong Kong has advocated an unprecedented emphasis on student learning, suggesting that teachers understand students' learning needs and apply tailor-made pedagogical design to maximize student learning (Lo, 2008). However, sustaining Lesson Study may be inhibited by many challenges, including teachers' pressures from the examination-oriented system, heavy workloads, pressures from parents and lack of support and trust among staff (Zhang, 2015). How to sustain Lesson Study in schools is yet to be explored, given few empirical studies have been conducted in the area. This study attempted to identify the strategies school leaders adopted to overcome challenges and promote Lesson Study in two Hong Kong schools (a primary school and a secondary school), which were selected as they had implemented Lesson Study for over 10 years. The study utilized qualitative research methods including interviews with school leaders (3-4 leaders from each school) and observation of leadership practices at management team meetings or in Lesson Study activities. Content analysis (Northcutt & McCoy, 2004) of the data from interviews and observations was conducted and the leadership practices enacted in the two case schools were coded with the five-category leadership practice model (Day & Leithwood, 2007; Hallinger, 2010): 1) establishing vision and setting directions for the school; 2) managing learning programmes; 3) understanding and developing staff in the school; 4) designing the organisation and cultivating a learning culture; and 5) managing internal and external resources to support school development. Descriptions of the leadership practices in the two schools were written up and put side by side for inter-school comparisons (Bray & Thomas, 1995) to identify common characteristics
