The aim of the research is to investigate how preschool teachers' content knowledge (CK) and pedagogical content knowledge (PCK) can be understood in relation to mathematics, science and technology (MST) in preschool i.e. the knowledge and values that underlie preschool teachers' choice of content and how it effects teaching in preschool. Teachers' knowledge of how children learn and the specific knowledge of how all children can be involved in the classroom is one of the components of PCK (Shulman, 1986) that together with issues of gender, class and ethnicity form the framework of the study. Data will be analysed with support of Shulman's theory (1986) and the sociocultural perspective (e.g. Rogoff, 2003, Wenger, 1998). A survey was conducted together with a reference group consisting of experienced preschool managers and preschool teachers. The survey is based on concepts that derive from Shulman (1986) and on the objectives spelled out in the national preschool curriculum (National Agency, 2016). The survey has been sent to 2000 Swedish preschool teachers and has been

analysed by multivariate methods. We follow ethical guidelines on anonymity and confidentially from the Swedish Research Council (2011). Findings provide knowledge on how preschool teachers talk about MST, what words they use and their pedagogical content knowledge in relation to their teaching about mathematics, science and technology. The findings show the preschool teachers PCK and also needs and dilemmas when teaching MST content in preschool activities.