For the sake of discussion to concentrating characteristics of multi dish concentrator, a simple calculation method of layout is given. By comparative study, the key of designing identical multi dish solar concentrator is confocal is deduced. In confocal and suitable f/D ratio conditions the smaller receiving aperture could be ensured, and the compound paraboloid receiver is not necessary. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.