Abstract: The significant influences of substituting low concentration Al at Zn-site as an anti-reflecting coating (ARC) for Zn1-xAlxO compound on structure; morphology and optical property have been studied. The Zn1-xAlxO sample with x = 0, 5, 10 and 15 wt.% were synthesized via a sol gel method. The films obtained from the sol gel method have been annealed at 400°C for 2 h. The XRD, SEM and AFM have been applied for characterizing the structure and the morphology of the film. XRD spectra show all samples exhibit hexagonal structure. The morphological measurements show that particle size decreases with increasing the concentration of Al. These films exhibit a denser and compact film`s structure that could be effective in light trapping in thin film solar cells. The optical property has been characterized using UV-Visible-NIR spectrometer. The values of band gaps increase as the concentration of Al increases. The increase of the band gap is acceptable as a requirement for good anti-reflecting coating element. Therefore these films can be applied as anti reflecting coating thin film solar cells.