Acetone,　a　small　molecule　organic　compound,　is　freely　soluble　and　volatile.　To　improve　the　removal　rate　of　acetone,　three　different　types　of　powdered　activated　carbon　(PAC)　were　compared　and　then　modified　with　formic　acid　and　NaOH　to　optimize　the　adsorption　capacities　of　PAC.　The　adsorption　mechanism　and　the　effect　of　physical-chemical　properties　of　PAC　to　the　adsorption　were　clarified.　Results　show　that　PAC　produced　from　wood　performed　best　adsorption　capacities.　The　pseudo-second-order　model　and　the　Freundlich　model　accurately　described　the　adsorption　behaviour,　while　lower　temperature　was　more　conducive　to　the　adsorption　process.　PAC　giving　a　higher　acetone　adsorption　capacity　had　a　larger　specific　surface　area,　a　richer　micropore　structure,　a　larger　micropore　volume,　a　smoother　surface,　with　more　acidic,　oxidizing　functional　groups.　The　adsorption　removal　efficiency　of　modified　PACs　with　formic　acid　was　improved　from　60.89%　to　82.93%,　while　NaOH　modification　decreased　the　adsorption　capacity.　The　positive　effect　of　formic　acid　was　attributed　to　the　formation　of　novel　acidic　oxygen-containing　functional　groups,　which　was　supported　from　the　NaOH　treatment　that　removed　original　acidic　oxygen-containing　functional　groups,　contrarily　the　formation　of　novel　alkaline　reducing　functional　groups　did　not　restore　the　acetone　adsorption　capacity.　We　conclude　that　wooden　PAC　is　a　suitable　adsorbent　for　acetone,　in　particular　after　pretreatment　with　formic　acid.