Thin films of SnO2 were prepared via wet chemical method and deposited by dip-coating on glass substrate. The annealing temperatures of the samples were 300, 400, 500 and 600o C, respectively. Water vapor sensor responses were measured and the experimental results are tested using the Freundlich model. The better water vapor sensitivities were obtained for annealing temperatures of 500 and 600oC, respectively. The samples were characterized morphological and structurally by SEM, XRD, Mössbauer spectroscopy and Raman spectroscopy. The fringes features in the ultraviolet-visible region indicate films thickness around 370 nm. The results are discussed in terms of the fine grain size of the samples.