Compared　with　the　widely　used　stable　oxygen　isotope　(δ18O),　the　climate　response　of　the　stable　carbon　isotope　(δ13C)　of　speleothems　in　monsoonal　China　has　received　less　attention,　mainly　because　of　its　relatively　complex　controlling　factors.　Nevertheless,　an　increasing　number　of　studies　are　suggesting　that　δ13C　can　represent　hydroclimatic　changes.　Here,　we　present　highly　resolved　continuous　δ13C　and　trace　element　ratio　records　of　a　speleothem　from　Wanxiang　Cave,　northwestern　China,　spanning　the　last　two　millennia.　Our　results　show　that　δ13C　values　oscillated　around　the　mean　value　on　centennial　scales,　indicating　that　the　overlying　vegetation　types　and　soil　humidity　did　not　change　significantly.　High　consistency　was　found　between　detrended　δ13C　and　δ18O　(δ13Cd　and　δ18Od)　records,　suggesting　that　soil　moisture　balance　and　vegetation　density　related　to　the　regional　hydrological　cycle　is　an　important　factor　controlling　δ13C　variations　on　multidecadal-centennial　scales.　The　regional　hydrological　cycle　is　mainly　controlled　by　summer　precipitation　induced　by　the　Asian　summer　monsoon　(ASM)　and　the　stable　prior　calcite　precipitation　(PCP),　which　was　inferred　from　trace　element　ratio　(Mg/Ca,　Sr/Ca,　Ba/Ca)　records.　The　δ13C　and　trace　element　ratio　records,　consistent　with　δ18O　throughout　the　considered　periods,　are　not　only　closely　coupled　with　the　intensity　of　the　El　Niño-Southern　Oscillation　and　north-south　shift　of　the　Intertropical　Convergence　Zone　but　also　respond　to　solar　activity　and　temperature　variations　in　the　Northern　Hemisphere.　However,　both　δ13C　and　trace　element　ratios　exhibited　a　persistent　significantly　decreasing　trend　in　the　last　150　years.　Furthermore,　the　variation　of　δ18O　during　the　Current　Warm　Period　(AD.　1850–2000)　suggests　that　anthropogenic　emissions　of　atmospheric　CO2　and　aerosols　rather　than　ASM　caused　an　unusual　increase　of　regional　precipitation　and　depletion　of　atmospheric　δ13C,　which　induced　increased　infiltration　of　atmospheric　CO2　and　available　water　into　soil　pores　and　caves　without　any　obvious　PCP　effect.　The　abnormal　changes　in　our　speleothem　δ13C　are　analogous　to　the　oceanic　13C　Suess　effect,　suggesting　that　stalagmite　δ13C　record　is　greatly　affected　by　atmospheric　CO2　concentration　under　global　warming.　©　2022　The　Authors