As part of a global steering trend partnership is emphasized in reform implementing in Western- Europa, and school leadership and school development is highlighted (Lingard & Ozga, 2007). School based professional development for teachers is a central part of the reform implementation. The subject in this study is the importance of school leaders in reform implementation, and I highlight the school leader’s role as reform implementer. Since the 70s researchers have been concerned about the ways educational policy is reconstructed, as it is put into place at schools and classrooms (Coburn, 2005; Tyack & Cuban, 1995). Early policy researchers attribute this to lack of skill and will by implementers, or to the implementers’ attempts to use reforms to meet their own goals (Coburn, 2005). A new line of research, with cognitive approach to policy implementation, is emerging. This research has shown that teachers come to understand new policy through the lens of their preexisting knowledge and practice, the local processes and social and cultural conditions of the teacher workplace, when they transform reforms (Coburn, 2005; Spillane, Reiser, & Reimer, 2002). Traditionally this research has been less engaged in leadership (Spillane et al., 2002), despite of the important role school leaders play in these processes. School leaders have a key role, but still we know little about how school leaders influence teachers’ sensemaking in reform transformation (Coburn, 2005). In this paper I highlight the school leaders’ sensemaking with their understanding of education policy and what constitutes “good instruction”, and their creation of conditions for teachers learning. Theories of sensemaking (Coburn, 2005; Spillane et al., 2002; Weick, 1976) and integrating political science, curriculum theory and education leadership theory, theory with different angles and emphasis, will form the basis of the empirical study enlightening the school leaders’ role. With a cognitive approach to policy implementation, I emphasize how school leaders’ affect teachers’ actions through their understanding of reform ideas when interacting with authorities, as well as through local adaption and engagement in the learning processes in different learning networks inside and outside the schools.