The　superconductivity　of　iron-based　superconductor　SmO0.7F0.2FeAs　was　investigated.　The　SmO0.7F0.2FeAs　sample　was　prepared　by　the　two-step　solid-state　reaction　method.　The　onset　resistivity　transition　temperature　is　as　high　as　56.5　K.　X-ray　diffraction　(XRD)　results　show　that　the　lattice　parameters　a　and　c　are　0.39261　and　0.84751　nm,　respectively.　Furthermore,　the　global　J(c)　was　more　than　2.3　x　10(5)　A/cm(2)　at　T　=　10　K　and　H　=　9　T,　which　was　calculated　by　the　formula　of　J(c)　=　20　Delta　M/[a(1　-　al(3b))].　The　upper　critical　fields,　H-c2　approximate　to　256　T　(T　=　0　K),　was　determined　according　to　the　Werthamer-Helfand-Hohenberg　formula,　indicating　that　the　SmO0.7F0.2FeAs　was　a　superconductor　with　a　very　promising　application.