Abstract
The orthographic projection is valid to describe object's shape in the two-dimensional surface. It is generally said that using the orthographic projection, even the most complex shape can be fully described. However, two pieces of objects which have the same borderline shapes on the six-views of each projection are invented. Furthermore , another object pairs with the same borderline shapes are confirmed too. In this paper, such objects are called Different Shape Objects which have the Same Six Views（DSO/SSV）.
