The　annular　fuel　assembly　was　designed　and　optimized　using　three-dimensional　neutronic/thermal-hydraulics　coupling　code.　Based　on　this　assembly,　the　core　design　was　also　carried　out.　In　the　annular　fuel　assembly,　the　feed　water　flows　through　the　center　hole　and　periphery　of　the　fuel.　This　brings　both　internal　and　external　cooling　for　the　fuel.　Because　of　this　character,　a　low　fuel　and　cladding　temperature　can　be　reached　with　relative　high　power　density.　The　water　in　the　center　hole　also　provides　sufficient　and　uniform　moderation　for　each　pin,　which　is　benefit　for　the　local　power　distribution.　DRAGON　was　used　for　assembly　calculation　to　get　the　macroscopic　cross　sections.　These　cross　sections　were　made　into　interpolated　table　for　core　calculation.　The　core　calculation　was　based　on　CITATION　and　auxiliary　depletion　code　CTBurn.　The　thermal　calculation　based　on　single　channel　model　was　used　to　obtain　water　density　distribution.　The　distribution　was　taken　as　feedback　for　neutronic　calculation.　The　results　show　that　SCWR　with　the　annular　fuel　assembly　is　a　promising　concept.