Biodegradable　dissolved　organic　carbon　(BDOC)　constitutes　the　most　labile　fraction　of　dissolved　organic　matter　(DOM),　which　also　functions　as　a　source　of　CO2　emissions　from　inland　waters.　However,　no　systematic　review　is　available　on　DOM　indicators　of　BDOC　and　CO2　production　potential.　Optical　and　molecular　indices　can　be　used　to　track　small　changes　in　DOM　composition　during　biodegradation.　In　this　review,　we　identified　four　different　methods　for　measuring　BDOC　together　with　their　strengths　and　limitations.　In　addition,　we　discuss　the　potential　of　using　documented　optical　indices　based　on　absorption　and　fluorescence　spectroscopy　and　molecular　indices　based　on　Fourier　transform　ion　cyclotron　mass　spectrometry　as　proxies　for　estimating　BDOC　and　biodegradation-induced　CO2　production　based　on　previously　reported　relationships　in　the　literature.　Many　absorbance-　and　fluorescence-based　indices　showed　inconsistent　relationships　with　BDOC　depending　on　watershed　characteristics,　hydrology,　and　anthropogenic　impacts.　Nevertheless,　several　indices,　including　specific　UV　absorbance　at　254　nm　(SUVA254),　humification　index　(HIX),　and　terrestrial　humic-like　fluorescent　DOM　(FDOM)　components,　tended　to　have　negative　relationships　with　BDOC　in　tropical　and　temperate　watersheds　under　baseflow　or　drought　periods.　Protein-like　FDOM　exhibited　the　strongest　correlation　with　BDOC　in　different　systems,　except　during　storms　and　flood　events.　Despite　the　limited　number　of　studies,　DOM　molecular　indices　exhibited　consistent　relationships　with　BDOC,　suggesting　that　the　relative　abundance　of　aliphatic　formulas　and　the　molecular　lability　index　could　act　as　reliable　proxies.　The　DOM　optical　indices　explain　up　to　96%　and　78%　variability　in　BDOC　and　CO2,　respectively;　nonetheless,　there　were　limited　studies　on　molecular　indices,　which　explain　up　to　74%　variability　in　BDOC.　Based　on　literature　survey,　we　recommend　several　sensitive　indices　such　as　SUVA254,　HIX,　and　terrestrial　humic-　and　protein-like　FDOM,　which　could　be　useful　indicators　of　BDOC　and　dissolved　CO2　in　inland　water.　Future　research　should　incorporate　a　wider　range　of　geographic　regions　with　various　land　use,　hydrology,　and　anthropogenic　disturbances　to　develop　system-　or　condition-specific　DOM　optical　or　molecular　proxies　for　better　prediction　of　BDOC　and　CO2　emissions.　©　2022　Elsevier　Ltd