In the era of educational change, the performance of middle-managers for schools development is critical. Much recent literature revealed that middle managers play an important role in school reforms (Blandford, 1997; Bennett, 1995; Fleming & Aamesbury, 2001). In Hong Kong, the EdB has specific job specifications for the middle managers, e.g., deputy headship, and coordination role in school curriculum, counseling and guidance, extra-curricular activities, etc. Usually each middle manager has to lead a group of teachers to achieve their goals assigned by the principal or the school management committee. The workload of middle managers in the Hong Kong primary schools has escalated dramatically with the implementation of a wide range of reform initiatives. In order to support the professional development of middle managers in primary schools, the Department of Educational Policy and Management of the Hong Kong Institute of Education started to offer a middle manager leadership programme in 2005. In addition to the systematic lectures and workshops, participants had to go through action learning which included role-play and action learning sharing. This paper aims to review the effectiveness of the programme, with special interest on action learning. Based on the empirical evidence from the semi-structured interview, participants reflected that they learned better in experiential in-service training.It seems that this kind of training is better for the professional development of middlemanagers in enhancing their ability on leading teams and management of school development.