Microsphere　has　shown　the　superiority　of　super-resolution　imaging　in　the　traditional　2D　intensity　microscope.　Here　a　microsphere　digital　holography　approach　is　presented　to　realize　the　resolution　enhancement　phase-contrast　imaging.　The　system　is　designed　by　combining　the　microsphere　with　the　image-plane　digital　holography.　A　microsphere　very　close　to　the　object　can　increase　the　resolution　by　transforming　the　object　wave　from　the　higher　frequency　to　the　lower　one.　The　resolution　enhancement　amplitude　and　phase　images　can　be　retrieved　from　a　single　hologram.　The　experiments　are　carried　on　the　1D　and　2D　gratings,　and　the　results　demonstrate　that　the　observed　resolution　has　been　improved,　meanwhile,　the　phase-contrast　image　is　obtained.　The　proposed　method　can　improve　the　transverse　resolution　in　all　directions　based　on　a　single　exposure.　Furthermore,　this　system　has　extended　the　application　of　the　microsphere　from　the　conventional　2D　microscopic　imaging　to　3D　phase-contrast　microscopic　imaging.　(C)　2015　Elsevier　B.V.　All　rights　reserved.