In　the　present　paper,　the　compact　ceramic　high　temperature　heat　exchangers　with　parallel　offset　strip　fins　and　inclined　strip　fins　(inclined　angle　beta=　0　similar　to　70　degrees)　are　investigated　with　CFD　method.　The　numerical　simulations　are　carried　out　for　high　temperature　(1500　degrees　C),　without　and　with　radiation　heat　transfer,　and　the　periodic　boundary　is　used　in　transverse　direction.　The　fluid　of　high　temperature　side　is　the　standard　flue　gas.　The　material　of　heat　exchanger　is　SiC.　Nu(S-G.R)(with　surface　and　gaseous　radiation　heat　transfer)　is　averagely　higher　than　Nu(No.R)　(without　radiation　heat　transfer)　by　7%　and　f(S-G.R)　is　averagely　higher　than　f(No.R)　by　5%.　Nu(S-G.R)(with　surface　and　gaseous　radiation　heat　transfer)　is　averagely　higher　than　Nu(S.R)　(with　only　surface　radiation　heat　transfer)　by　0.8%　and　f(S-G.R)　is　averagely　higher　than　f(S.R)　by　3%.　The　thermal　properties　have　significantly　influence　on　the　heat　transfer　and　pressure　drop　characteristics,　respectively.　The　heat　transfer　performance　of　the　ceramic　heat　exchanger　with　inclined　fins　(beta=30　degrees)　is　the　best.