The　adsorption　characteristics　and　influencing　factors　of　two　azo　dyes(direct　sunlight-resistant　peach　red-BK　and　reactive　brilliant　orange　X-GN)　on　different　kinds　of　powdered　activated　carbon　(PAC)　were　studied.　The　physical　and　chemical　properties　of　the　three　PACs　were　characterized.　The　adsorption　kinetics,　isotherm　and　mechanism　involved　of　PAC　on　typical　azo　dyes　were　analyzed.　The　results　indicate　that　the　best　adsorption　effect　of　azo　dyes　can　be　obtained　with　the　largest　BET-specific　surface　area　and　less　surface　sintering　and　the　highest　number　of　mesoporous　and　macro-porous　of　PAC,　which　is　high　in　oxygen　elements　and　mainly　consists　of　acidic　functional　groups　such　as　C=O,　-OH　and　-COOH.　The　adsorption　of　azo　dyes　onto　PAC　is　inhomogeneous,　including　surface　adsorption,　external　liquid　membrane　diffusion　and　intra-particle　diffusion　as　well.　Azo　dye　molecules　are　mainly　adsorbed　in　the　mesoporous　(macro-porous)　of　PAC,　and　the　initial　stage　is　dominated　by　rapid　adsorption　followed　by　diffusion　in　the　later　stage.　The　adsorption　kinetics　fit　well　with　the　pseudo-second-order　kinetics　model,　and　the　adsorption　isotherms　follow　amendatory　Freundlich　equation.　The　main　mechanism　of　azo　dyes　adsorbed　on　PAC　is　mainly　chemisorption　and　predominated　by　hydrogen　bonding,　Van　der　Waals　interaction　force,　as　well　as　electrostatic　interaction　of　the　functional　groups　between　PAC　surface　and　dye　molecular.　©　2019,　Central　South　University　Press.　All　right　reserved.