GaAs films grown on ferroelectric SrTiO3 substrates by molecular beam epitaxy are characterized, to the best of our knowledge, for the first time by using photoluminescence (PL), scanning electron microscopy and secondary-ion mass spectrometry measurement techniques. The results show that under the current growth conditions the deposited GaAs material first forms 3D islands on the SrTiO3 substrates and then with further increase in deposition thickness of GaAs, a GaAs film with a very rough surface is formed. Optical transitions close to GaAs band-gap energy are observed for both the thin and the relatively thick samples. The transition energy of the observed emission labeled as F in the PL spectra shows a significant blue shift in comparison with the energy of the band-gap emissions in bulk GaAs.