Today, curved beams are extensively used in many fields, such as in the rounded corners of building, circular balconies, …etc and composite materials are extensively used in building industry, because of their high strength to weight ratio. The research deals with the analysis of horizontal composite sandwich curved beam with foam core, loaded transversely to its plane, using a three dimensional nonlinear finite element model to the ultimate load.The beam is included foam core of Divinycell H250 and top and bottom layers that each one has 10 layers of carbon fiber reinforced epoxy material that thickness of each layer of composite is also 0.5 mm. The beam has orthotropic carbon epoxy layers at its top and its bottom and a crushable foam as its core. Symmetrical orders of the layers were changed and ultimate strength and failure modes were studied. The tensile failures mode is matrix were observed in the first few failures of the layers and then the other failure modes were occurred. The sequential orders of the layers have a great impact on the ultimate strength and also on the failure modes of the layers.