We have fabricated the europium (Eu) doped Ga2O3 thin films on GaAs substrate by using pulsed laser deposition. The impact of Eu contents on structure, surface morphology, and optical properties are systematically investigated. We demonstrate that the Eu contents in Ga2O3 films can be controlled by adjusting the Eu contents in the targets. Moreover, all the films exhibited monoclinic Ga2O3 structure and smooth surface. We also clearly observe intense red emissions at 611 nm for the Eu doped Ga2O3 films. It is believed that this work paves the way for the development of GaAs-based red electroluminescence devices by using wide bandgap Ga2O3 as the host materials for Eu3+ ions.