The　skutterudite　(Fe/Ni)(x)Co4-xSb12　(X=0-1.0)　compounds　were　prepared　by　spark　plasma　sintering　(SPS)　technique　at　800-1000K　using　Co,　Sb,　Fe　and　Ni　powder　as　raw　materials.　The　thermoelectric　properties　of　(Fe/Ni)(x)Co-4-Sb-12　(x=0-1.0)　compounds　are　investigated　systematically.　The　results　indicate　that　the　thermal　conductivity　and　lattice　thermal　conductivity　of　p-type　FexCo4-Sb-12　compounds　decrease　with　the　increasing　Fe　filling　fraction.　The　thermal　conductivity　of　n-type　NixCo4-xSb12　compounds　reach　the　minimum　value　when　the　Ni　filling　fraction　is　0.2,　and　the　lattice　thermal　conductivity　reduce　evidently　with　the　increasing　Ni　content.　The　electrical　conductivity　and　carrier　concentration　of　(Fe/Ni)(x)Co4-xSb12　Compounds　increase　with　the　increasing　Fe,　Ni　content,　and　the　Seebeck　coefficient　decreases　with　the　increasing　Fe,　Ni　content.　In　contrast　with　Fe　substitution,　Ni　filling　shows　a　more　positive　effect　on　the　optimization　of　thermoelectric　properties　of　CoSb3-based　skutterudite　compounds.　In　this　study,　the　obtained　maximum　ZT　value　reaches　0.6　for　n-type　Ni0.2Co3.8Sb12　at　800　K.　(c)　2007　Elsevier　B.V.　All　rights　reserved.