<1> The standing MHD-waves in the potential magnetic arcades describing the bipolar active regions are investigated. The eikonal method allows us the analytical study of the short waves which are divided into the Alfvin and magnetosonic waves. The eigen modes of the magnetic arcades are formed as a result of their reflection from the photosphere. The Alfvin mode oscillations of the certain frequency take place on the magnetic surfaces. The fast mode oscillations also take place on some surfaces but they are not magnetic. Each oscillation surface has a discrete set of the eigen frequencies.