Qualitative changes in teachers’ ways of talking about teaching and science as content in preschool practicepresentationsformat: Muntlig presentationabstract: The aim of the research project presented here is to analyze and describe how pre-school teachers during an in-service training period develop theoretical knowledge about focusing the content when planning for teaching science in pre-school. This particular training period can be seen as needed due to a new school law and a revised curriculum for Swedish pre-schools in 2011, where the concept teaching in pre-school is used for the first time and different content areas as mathematics and science is highlighted. The variation theory is here used as a framework for analysis as well as for the pre-school teachers planning for teaching in pre-school (Marton & Booth, 1997). The theory is developed from the phenomenographic approach and can be described in terms of learning object, critical aspects, discernment, simultaneity, variation and a shared space of learning (Marton, 2014). The results in a phenomenographic study is an outcome space of categories describing qualitatively different ways of experiencing the same phenomenon. 30 pre-school teachers from 10 different pre-schools in nine different municipalities participated in the project. The empirical material consist of a questionnaire with open ended questions as the preschool teachers answered in the beginning and in the end of the training period, and of group reports as were written from scientific projects. The study has followed the ethical guidelines of the Swedish Research Council (2002). The results can be discussed as a number of critical aspects in relation to teachers' learning as: ways of understand the concept of variation, to discern the object of learning and a shared space of learning. One important factor to point out concerning the design of in-service training is the importance of keeping together theories of children’s learning and the learning object (science).Key-word: Preschool teacher, In-service training, Teaching, Science, Variation theory, Phenomenography