Coastal　buildings　are　exposed　to　salt　spray　environments　for　prolonged　periods　of　time,　and　salt　accumulates　in　the　building　walls.　The　effect　of　salt　on　the　water　absorption　characteristics　of　the　material　is　unclear　and　requires　further　investigation　of　the　coupled　heat　and　moisture　transfer　processes　in　coastal　building　walls.　To　address　this　issue　and　quantify　this　effect,　cement　mortar　specimens　were　pretreated,　and　a　capillary　water　absorption　experiment　was　conducted　on　a　salt-containing　cement　mortar　to　obtain　the　laws　of　the　water　absorption　coefficient　and　capillary　saturation　moisture　content　with　salt　content.　In　addition,　equations　for　fitting　the　water　absorption　coefficient　and　capillary　saturation　moisture　content　of　salt-containing　materials　were　established　by　integrating　the　salt　impact　factors　proposed　in　this　study.　The　obtained　results　showed　that　as　the　salt　content　increased,　the　water　absorption　coefficient　first　increased　and　then　decreased,　with　a　peak　increase　of　7.5%　compared　to　that　of　the　control　group.　The　capillary　saturation　moisture　content　gradually　decreased　with　increasing　salt　content,　decreasing　by　15.8%　at　the　maximum　salt　content.　Combined　with　scanning　electron　microscopy　(SEM)　observations　of　microstructural　changes　in　specimens　containing　different　amounts　of　salt,　it　was　inferred　that　the　dominant　factors　affecting　the　water　absorption　characteristics　would　be　different　when　the　salt　content　of　the　material　was　varied.　In　addition,　the　optimal　formulae　for　the　water　absorption　coefficient　and　capillary　saturation　moisture　content　of　salt-containing　materials　were　obtained.　©　2023　Elsevier　Ltd