Within the discipline of early childhood education research, the present study will focus on the Swedish preschool curriculum text, using a sociomaterial approach offered by Actor-network theory (ANT). The study adopts ethnographic methods, foremost participant observations in a preschool, to generate knowledge of how the curriculum text comes to act through moments in the everyday preschool work. The doctoral thesis consists of three research papers. Research paper I explores the delayed access to the field through the occurrence of a water leak. Through the focus on the value of breakdowns in ANT, the water leak becomes an empirical event where the researcher is allowed to learn about the mundane objects and practices making a preschool work, such as schedules and lists. Research paper II reports on the case of the curriculum concept of children´s interests (Moberg, 2017). Here, empirical moments are highlighted where the curriculum concept of children´s interests is defined and made to act by children and materialities. Finally, research paper III (Moberg, in press) reports on the case of an evaluation meeting where an evaluation text is to be produced. Here, the curriculum text is highlighted as vulnerable in its inability of embracing pedagogical dilemmas and ambivalence in the preschool everyday work.