This　paper　introduces　a　self-localization　method　depending　on　two　signposts　for　onmi-directional　robots.　In　the　real　environment　because　of　keeping　out　or　the　intensity　of　the　ray,　the　robot　can＇t　find　enough　signposts　for　self-localization.　But　in　the　past　the　robot　needs　at　least　three　signposts　for　self-localization.　So,　using　the　advantage　of　the　onmi-directional　vision,　this　paper　gives　a　new　method　depending　on　two　signposts　for　self-localization.　This　method　reduces　the　searching　time　in　the　Robocup　competition　or　robot　navigation.　The　result　of　the　experiments　shows　the　method　is　very　precise.