To find out the differentiations in elementary preservice teachers' conceptions of weathering and erosion, thirty items were developed as sentences stating the contents of weathering and erosion. These items were used as questionnaire to fill out whether each item is weathering, erosion or common to the two. The results are as follows. First, knowledges of the processes and elements in both weathering and erosion were relatively good, but the objects and outcomes were lacking. Second, knowledges of the contents common to the two were lacking. Third, the knowledges about the kinds, lowering of pressure upon rocks, plants roots' workings, water freezing in weathering and those about glaciation, rock erosion on desert in erosion were lacking.