This　letter　proposes　a　novel　scheme　for　spatial　steganalysis　based　on　contrast　of　residuals　(CoR).　After　selecting　complex　blocks　from　an　uncompressed　image　by　a　fluctuation　function,　the　residuals　are　calculated　from　the　selected　blocks　and　the　whole　image　after　applying　diverse　filters.　The　CoR　is　represented　as　an　angle　and　the　norm　of　residuals　is　considered　as　the　corresponding　weight　of　angle,　which　is　used　as　the　new　steganalysis　feature.　In　the　proposed　scheme,　no　quantization　and　truncation　is　required　and　the　effective　information　of　long-range　dependencies　among　pixels　is　kept　properly.　Also,　the　dimensionality　of　feature　is　linear　with　the　number　of　residuals.　The　accuracy　of　proposed　scheme　is　evaluated　on　HUGO　and　WOW　algorithms,　and　the　experimental　results　show　that　the　proposed　CoR　feature　has　superior　performance　at　low　embedding　rate　with　lower　dimensionality.　©　1994-2012　IEEE.