The　objective　of　this　research　is　to　study　the　properties　of　waterborne　epoxy-modified　emulsified　asphalt　binder　(WEMEAB).　The　WEMEAB　was　prepared　with　a　method　of　preemulsification　and　modification.　The　optimum　asphalt-water　ratio　(ratio　of　base　asphalt　binder　to　emulsifier),　emulsifier　content,　and　waterborne　epoxy　content　were　determined　through　an　orthogonal　test　with　three　factors　and　three　levels.　Based　on　the　penetration　system,　the　high-　and　low-temperature　properties　and　storage　stability　of　WEMEAB　were　evaluated.　The　distribution　of　waterborne　epoxy　in　the　modified　emulsified　asphalt　binder　and　the　microstructure　of　WEMEAB　were　observed　through　the　Fluorescence　Optical　Microscopy　(FOM)　and　Atomic　Force　Microscopy　(AFM)　tests.　The　test　results　indicated　that　the　high-　and　low-temperature　properties　of　WEMEAB　were　noticeably　improved　and　that　the　waterborne　epoxy　was　distributed　uniformly　in　the　modified　emulsified　asphalt　binder　with　an　asphalt-water　ratio　of　65:35,　4　%　waterborne　epoxy　and　1.4　%　emulsifier.　The　FOM　and　AFM　images　showed　that　cross-linking　and　interpenetration　network　structure　and　＂bee-like＂　structures　had　formed　on　the　surface　of　the　WEMEAB.