Accurate　topography　of　intertidal　mudflats　of　a　fine　resolution　is　fundamental　data　to　further　understand　the　coastal　process　and　achieve　targeted　coastal　management.　However,　the　mapping　of　mudflat　topography　is　hindered　by　poor　accessibility　of　muddy　environments　and　a　short　observation　time　window　caused　by　periodic　tides.　Commonly　as　a　revolutionary　technique　owing　to　its　low　cost,　flexibility,　and　quality　data,　the　unmanned　aerial　vehicle　(UAV)-based　SfM　photogrammetry　has　been　widely　applied　in　coastal　areas.　The　conventional　UAV　photogrammetric　accuracy　significantly　depends　on　the　number　and　distribution　of　ground　control　points　(GCPs),　limiting　its　mapping　efficiency.　With　the　increasingly　available　UAVs　with　onboard　RTK,　photogrammetry　without　GCPs　is　becoming　a　promising　alternative.　However,　the　ability　of　this　advanced　RTK-assisted　UAV　to　capture　centimeter-scale　elevation　changes　in　intertidal　mudflats　still　remains　unclear.　For　this　reason,　this　paper　aims　to　evaluate　the　potential　of　RTK-assisted　UAVs　in　quantifying　intertidal　topographic　changes.　The　results　showed　that　the　RTK-assisted　UAV　structure-from-motion　(SfM)　photogrammetry　without　GCPs　could　accurately　capture　fine-scale　topographical　features　such　as　mudflat　gradient　and　creeks　with　root-mean-squared　errors　(RMSE)　of　±　3.3　cm,　±　2.8　cm,　and　±　4.7　cm　on　X-,　Y-,　and　vertical　directions,　respectively.　Therefore,　this　study　identified　that　RTK-assisted　UAV　photogrammetry　could　be　used　to　quantify　intertidal　mudflat　morphodynamics　and　calculate　sediment　deposition　volume　within　the　uncertainty　in　a　more　cost-effective　way.　©　2022　IEEE.