We have investigated the behavior of water adsorption on alkali halide surfaces in air at room temperature using the noncontact monitoring mode of a scanning force microscope (SFM). We have found a formation of water droplet pattern on LiF (001) surface and subsequent formation of a uniform film, as reported on BaF₂(111) surface. However, no water droplet pattern was observed on NaCl (001) surface. The SFM image from NaF (001) surface has revealed complicated features with water droplet pattern. The different H₂O adsorption patterns for LiF, NaF and NaCl seem to be induced by the competition between water-water and water-substrate interactions.