The　coastal　urban　region　is　generally　considered　an　atmospheric　receptor　for　terrestrial　and　marine　input　materials,　and　rainfall　chemistry　can　trace　the　wet　scavenging　process　of　these　materials.　Fast　urbanization　in　China＇s　east　coastal　areas　has　greatly　altered　the　rainwater　chemistry.　However,　the　chemical　variations,　determinants,　and　sources　of　rainfall　are　unclear.　Therefore,　the　typical　coastal　city　of　Fuzhou　was　selected　for　1-year　rainwater　sampling　and　inorganic　ions　were　detected　to　explore　above　problems.　The　findings　depicted　that　rainwater　ions　in　Fuzhou　were　slightly　different　from　those　in　other　coastal　cities.　Although　NO3-,　SO42-,　Ca2+　and　NH4+　dominated　the　rainwater　ions,　the　marine　input　Cl-　(22　%)　and　Na+　(11　%)　also　contributed　a　considerable　percentage　to　the　rainwater　ions.　Large　differences　in　ion　concentrations　(2　similar　to　28　times)　were　found　in　monthly　scale　due　to　the　rainfall　amount.　Both　natural　and　anthropogenic　determinants　influenced　the　rainwater　ions　in　coastal　cities,　such　as　SO2　emission,　air　SO2　and　PM10　content　on　rainwater　SO42-,　NO3-,　and　Ca2+,　and　soot　&　dust　emission　on　rainwater　SO42-,　NO3-,　indicating　the　vital　contribution　of　human　activities.　Stoichiometry　and　positive　matrix　factorization-based　sources　identification　indicated　that　atmospheric　dust/particles　were　the　primary　contributor　of　Ca2+　(83.3　%)　and　F-　(83.7　%),　and　considerable　contributor　of　SO42-　(39.5　%),　NO3-　(38.3　%)　and　K+　(41.5　%).　Anthropogenic　origins,　such　as　urban　waste　volatilization　and　fuel　combustion　emission,　contributed　95　%　of　NH4+,　54.5　%　of　NO3-　and　41.9　%　of　SO42-,　and　the　traffic　sources　contribution　was　relatively　higher　than　fixed　emission　sources.　The　marine　input　represented　the　vital　source　of　Cl-　(77.7　%),　Na+　(84.9　%),　and　Mg2+　(55.3　%).　This　work　highlights　the　significant　influence　of　urban　human　activities　and　marine　input　on　rainwater　chemicals　and　provides　new　insight　into　the　material　cycle　between　the　atmosphere　and　earth-surface　in　coastal　city.