This article compares and discusses three prevailing approaches used to understand the concept of school culture and school culture phenomena. The approaches are typology-functionalist approach, process approach, and improvement-effectiveness approach. Compared with the other two, improvement-effectiveness approach is identified as more appropriate to conceptualize school culture when the concept is applied to promote school improvement and effectiveness. Moreover, the School Improvement Model of School Culture developed by Cavanagh and Dellar is introduced with the implications of the model to Hong Kong school leaders, policy-makers and educational researchers are being discussed. Copyright © 2009 Hong Kong Teachers’ Centre.