In　this　paper,　the　effects　of　river　sand,　sea-sand,　recycled　sand,　and　shell　sand　on　the　carbonation　performance　of　recycled　aggregate　concrete　(RAC)　were　studied.　The　results　showed　that　the　carbonation　depth　of　RAC　prepared　from　sea-sand　was　89.8-96.8　%,　83.8-93.4　%,　and　70.5-84.8　%　of　that　prepared　from　recycled　sand,　shell　sand,　and　river　sand,　respectively.　The　compressive　strength　of　RAC　made　from　sea-sand　was　the　highest,　followed　by　RAC　made　from　river　sand,　shell　sand,　and　recycled　sand.　The　chloride　ions　in　the　sea-sand　promoted　the　formation　of　Friedel＇s　salt　and　C-S-H　with　a　high　Ca/Si　ratio,　increasing　the　density　of　the　concrete,　thereby　blocking　the　CO2　diffusion　channel　and　reducing　the　carbonation　rate.　On　the　other　hand,　the　weak　strength　and　bond　of　shell　sand,　and　the　weak　interfacial　transition　zone　of　recycled　sand　resulted　in　weak　concrete　microstructure.　In　this　paper,　after　90　days　of　carbonation,　the　increment　of　CaCO3　for　preparing　RAC　from　sea-sand　was　95.1　%,　67.7　%,　and　37.7　%　of　that　of　river　sand,　shell　sand,　and　recycled　sand,　respectively.　The　RAC　made　of　shell　sand　or　recycled　sand　had　a　porous　microstructure,　which　provided　sufficient　growth　space　for　CaCO3,　and　its　total　porosity　was　significantly　reduced　after　carbonation.　Finally,　a　prediction　model　of　RAC＇s　carbonation　depth　was　proposed,　which　was　highly　consistent　with　the　experimental　results.　The　mean　error　of　the　model　was　close　to　1.0　and　the　COV　was　0.169.