Environmental education in schools is an important strategy in achieving environmental improvement. However, it needs to be based on children's understandings of environment rather than on assumptions of what children know and believe. This paper reports on a research project where school children's answers to a question 'I think the term/word environment means...' were analysed using the qualitative research method of phenomenography. Six distinct conceptions were isolated, ranging from the least sophisticated - environment as a place - to the most inclusive and expansive - environment and people in a relationship of mutual sustainability. An important qualitative difference was found between conceptions that treat the environment as an object and relational conceptions. The implications of these findings for environmental education are discussed.