Power　station　fly-ash　cenosphere　particles　were　plated　with　metal　to　prepare　a　light　weight　microwave　absorbing　material.　The　plating　used　an　economical　copper　replacement-deposition　method　that　differs　from　general　electrodeless-plating　pretreatment.　The　reaction　time　was　reduced　to　1.5　h,　with　the　process　reduced　to　three　steps　with　much　lower　cost.　The　microwave　absorption　characteristic　of　the　product　depends　on　the　metal　deposition　time.　The　results　show　that　the　fly-ash　cenosphere　particles　have　good　microwave　absorption　characteristics　after　the　metal　deposition.　Coatings　with　thicknesses　of　0.7-0.8　mm　gave　a　maximum　microwave　absorption　of　-16　dB　with　a　band　width　of　larger　than　2　GHz.　The　absorption　was　less　than　-10　dB　for　frequencies　of　8-18　GHz.