ABSTRACTIn spite of the use to which aerial photographs have been put in southern Ontario, there has not yet been developed a complete key for the interpretation of landforms. Accordingly, a beginning has been made on this work by the authors as a project in the Department of Geography in the University of Toronto. Certain landforms such as river valleys andescarpments are easily interpreted, but most of the forms of the glaciated landscape are not easily identified. The factors which are used in identifying lands are shape, tone, texture and shadow. Man‐made patterns often provide a clue to the nature of the landform. Such a key cannot be developed without personal experience in the reading of the photographs on the ground in the exact area in which the interpretation was made. It is from the personal experience of the authors in different areas of southern Ontario that this key has been prepare