This　paper　introduces　a　self-localization　method　depending　on　two　signposts　for　onmidirectional　robots.　In　the　real　environment　because　of　keeping　out　or　the　intensity　of　the　ray,　the　robot　can＇t　find　enough　landmarks　for　self-localization.　But　in　the　past　the　robot　needs　at　least　three　signposts　for　self-localization.　So,　depending　on　the　advantage　of　the　onmidirectional　vision,　this　paper　gives　a　new　method　using　two　signposts　for　self-localization.　This　method　reduces　the　searching　time　in　the　Robocup　competition　or　robot　navigation.　The　experimental　results　show　the　method　is　very　precise.　©　2008　IEEE.