The effect of the pulsed – laser annealing on the parameters of CdS thin layers in the medium of oxygen was studied. The CdS thin layers were deposited by spray pyrolysis at different technological conditions. The changes of the layers’ characteristics were studied by SEM, XRD and XPS and electrical measurements were carried out. The results showed that a change in the morphology and the phase composition of the surface occurred; a by-surface layer consisted of CdО with high conductivity was formed in consequence of oxidation of CdS. The parameters of the CdS thin layers were retained in- depth after pulsed laser annealing. These results are discussed in the context of transparent layers in solar cells.