The author is pointing out some local properties of finite and infinitesimal deformation of a continuum. We mention here some of these properties. Let x be the place of the particle X in deformation \(x=x(X)\). It is shown that at every place x there exists at least a plane such that there is no shearing for all material elements instantaneously in this plane. A plane having this property is referred to as a special plane. It is also proved that the planes of the central circular sections of the spatial strain ellipsoid at x are deformed into planes of the central circular sections of the material strain ellipsoid at x, and that the only special planes at x are those containing the central circular sections of the spatial strain ellipsoid. The case of infinitesimal strain is also considered.