A simple synthetic route was developed for the synthesis of anatase TiO₂ nanoparticles with tunable dominant exposed facets. These nanoparticles were characterized by XRD, TEM, XPS and EDS measurements. The F⁻ ions displayed a key role in the hydrothermal reaction for the formation of anatase TiO₂ with different exposed facets (010), (001) and (106), which were decided by the different connection models of Ti–OH. Furthermore, a possible mechanism for the formation of anatase TiO₂ with different exposed facets was suggested.