Dicarboxylic　acids　are　strong　hygroscopic　organic　compounds　in　the　atmosphere,　and　thus　significantly　affect　the　cloud　formation　process　and　radiative　forcing　on　a　regional　scale.　So　far,　the　evolution　of　dicarboxylic　acids　during　vertical　transport　from　the　surface　to　the　mountaintop　has　yet　to　be　explicitly　understood.　In　this　study,　the　molecular　distribution　and　stable　carbon　isotopic　(δ13C)　compositions　of　dicarboxylic　acids　and　related　organic　compounds　(DCRCs)　in　PM2.5　were　measured　simultaneously　at　the　top　(c.　2060　m　a.s.l.)　and　foot　(c.　400　m　a.s.l.)　of　Mount　(Mt.)　Hua　during　the　summer　of　2020.　Due　to　the　strong　anthropogenic　emissions　at　ground　level,　the　concentrations　of　DCRCs　at　foot　of　Mt.　Hua　were　generally　higher　than　those　at　the　top.　Oxalic　acid　(C2)　was　the　predominant　diacid　in　both　sites,　whose　concentrations　at　foot　and　top　of　Mt.　Hua　were　87–852　and　40–398　ng　m−3,　respectively.　Ratios　of　adipic　acid　to　azelaic　acid　(C6/C9),　phthalic　aid　to　azelaic　acid　(pH/C9),　glyoxal　to　methylglyoxal　(Gly/mGly),　and　lower　δ13C　values　(−21.0　±　2.3　‰　and　−　21.9　±　2.7　‰)　of　C2　indicated　that　the　contributions　of　anthropogenic　sources　to　DCRCs　in　PM2.5　in　the　mountain　region　are　more　significant　than　biogenic　sources.　Aerosols　from　the　foot　of　Mt.　Hua　could　affect　the　atmosphere　on　the　top　of　the　mountain　via　vertical　transport　under　the　influence　of　daytime　valley　wind,　even　though　the　altitude　of　Mt.　Hua　is　beyond　the　boundary　layer　most　of　time.　The　value　δ13C　of　C2　is　linearly　correlated　with　C2/mGly,　C2/pyruvic　acid　(Pyr),　C2/glyoxylic　acid　(ωC2)　at　the　top　of　the　mountain,　and　C2/Gly,　C2/ωC2　at　the　foot　of　the　mountain,　indicating　that　the　formation　pathway　of　C2　is　mGly-Pyr-ωC2-C2　at　the　top　of　Mt.　Hua　and　Gly-ωC2-C2　at　the　foot　of　Mt.　Hua.　©　2022　Elsevier　B.V.