This　paper　presents　a　novel　method　for　measuring　whole　field　in-plane　displacement　by　using　optical　fiber　phase-shifting　ESPI.　A　1　x　4　single　mode　optical　fiber　beamsplitter　is　employed　to　split　the　laser　beam　into　four　beams　of　equal　intensity.　We　use　one　pair　of　fibers　to　illuminate　the　diffuse　target　at　equal　angles　in　the　horizontal　plane　so　it　is　sensitive　only　to　horizontal　in-plan　displacement.　Another　pair　of　optical　fibers　is　set　to　be　sensitive　only　to　vertical　in-plane　displacement.　The　polarization　directions　of　light　emitted　by　fibers　are　same　for　each　pair　but　are　at　right　angle　between　pairs.　The　optical　fibers　are　equal　in　length　for　each　pair　but　are　not　equal　between　two　pairs.　In　this　case　the　speckles　are　interference　itself　for　each　pair　fibers,　respectively,　so　we　can　get　the　horizontal　and　vertical　displacement　components　simultaneously.　By　means　of　fiber　phase　shift　technique　we　can　displacement　of　a　thin　metal　plate,　and　the　examples　of　the　results　obtained　are　shown　to　demonstrate　obtain　the　quantitative　data　of　whole　field.　This　method　has　enabled　to　study　the　in-plane　displacement　of　a　thin　metal　plate,　and　the　examples　of　the　results　obtained　are　shown　to　demonstrate　the　novel　method.