In this paper, we report the fabrication of Si-based double-hetero-epitaxial silicon on insulator (SOI) structure Si/γ-Al 2O 3/Si. Firstly, single crystalline γ-Al 2O 3(1 0 0) insulator films were grown epitaxially on Si(1 0 0) using the sources of TMA (Al(CH 3) 3) and O 2 by very low-pressure chemical vapor deposition. Afterwards, Si(1 0 0) epitaxial films were grown on γ-Al 2O 3 (1 0 0)/Si(1 0 0) epi-substrates using a chemical vapor deposition method similar to the silicon on sapphire epitaxial growth. The Si/γ-Al 2O 3/Si SOI materials are characterized in detail by reflect high-energy electron diffraction, X-ray diffraction and Auger energy spectrum (AES) techniques. The insulator layer of γ-Al 2O 3 has an excellent dielectric property. The leakage current is less than 1×10 −10 A/cm 2 when the electric field is below 1.3 MV/cm. The Si film grown on γ-Al 2O 3/Si epi-substrates was single crystalline. Meanwhile, the AES depth profile of the SOI structure shows that the composition of γ-Al 2O 3 film is uniform, and the carbon contamination is not observed. Additionally, the γ-Al 2O 3/Si epi-substrates are suitable candidates as a platform for a variety of active layers such as GaN, SiC and GeSi. It shows a bright future for microelectronic and optical electronics applications.