Ferroelectric BaTiO3 thin films were epitaxially grown on rutile-TiO2 buffered GaAs(001) substrates by pulsed laser deposition system. The in-plane relationship of this heterostructure is < 110 > BaTiO3// < 001 > TiO2// < 110 > GaAs and the out-plane relationship is BaTiO3(110)//TiO2(110)//GaAs(001). The surface of BaTiO3 is flat and the interfaces between each layer are clear. The oxygen vacancies were eliminated by ex-situ annealing in adequate O-2. In short, a highly (110)-oriented BaTiO3 thin film was grown on TiO2 buffered GaAs (001) substrate with excellent electrical and structural properties. The BaTiO3(150 nm)/TiO2(40 nm)/GaAs system demonstrates hysteresis loops with a remnant polarization of 2.6 mu C/cm(2) and a small leakage current density of 1 x 10(-6) A/cm(2) both at 300 kV/cm. (C) 2017 Elsevier B.V. All rights reserved.