In the new Swedish National Curriculum for Preschool (Lpfö 98, rev. 2010) the corner stones are learning, play, education and care. Preschool is today part of the common school system and to reach the national goals planning, assessment, follow up and development are essential aspects. The aim of this longitudinal study is to develop a link between science, practice and preschool education in order to strengthen the scientific basis and raise the quality in preschool. Focus is on implementation of the curriculum and quality work. Data are collected with questionnaires and interviews. The systematic quality work will at sight lead to increased learning, health and well-being in the children.