The aim of this research was to analyze preschool teachers' types of science talks and the variety of concept-related words they used during these talks in class. A picture storybook with a light related concept as the main theme, was chosen as a data collection tool. Teachers were asked to analyze this wordless picture storybook and children were asked in their classes if they approved it. Ten preschool teachers in-service participated in this research. Data were qualitatively collected; it was recorded during story telling. Research results showed that teachers included science explanations, declarative scientific knowledge, questions, comparisons, and evidence talks supporting thinking skills, among types of science talks according to their frequency order, whereas they did not include personal connections talk. Besides, it was determined that they included light related concepts (natural and artificial), vision related concepts (daylight/darkness, like difficulty in vision) and light direction related concepts, according to their frequency order. It can be stated that the results obtained from this research shall contribute to framing of contents of professional development particularly scientific activities of teachers.