Barium oxide transparent thin films have been deposited on glass substrate by a chemical spray pyrolysis (csp) technique. Surface investigations such as XRD and AFM, and patterns of the films were investigated for asdeposited and annealing in (4bar). By XRD, the polycrystalline phase is identified for as-deposited films and it stay polycrystalline with the (100) and (101) as preferentail crystallographic orientation for annealed samples .The morphology of the films is strongly related to the annealing temperature. The as-deposited films exhibited highest optical transmittance and the direct band gap energy was found to vary from (2.4 - 2.7) eV with annealing.