An epitaxial structure is provided. The epitaxial structure includes a substrate, an epitaxial layer and a carbon nanotube layer. The epitaxial layer is located on the substrate. The carbon nanotube layer is located between the substrate and the epitaxial layer. The carbon nanotube layer can be a carbon nanotube film drawn from a carbon nanotube array and including a plurality of successive and oriented carbon nanotubes joined end-to-end by van der Waals attractive force therebetween.