Chemical　looping　dry　reforming　of　methane　is　an　attractive　approach　to　use　carbon　dioxide　and　methane,　the　two　most　abundant　greenhouse　gases.　For　this　scheme,　the　redox　material　(or　oxygen　carrier)　plays　a　key　role.　It　is　of　great　significance　to　improve　the　redox　performance　of　strontium　ferrite　(SrFeO3-δ,　SFO),　a　low-cost　and　easily　tunable　perovskite-typed　oxygen　carrier.　Here,　we　present　the　effect　of　composition　on　the　redox　performance　of　SrFeO3-δ　confined　in　the　matrix　of　calcium　oxide　(CaO).　The　nanocomposites　were　prepared　by　the　Pechini　method,　and　the　redox　performance　was　evaluated　in　a　fixed　bed　tubular　quartz　reactor　at　980　°C　and　atmospheric　pressure.　In　the　characteristic　reduction　time,　10　wt　%　SrFeO3-δ-CaO　nanocomposite　exhibits　the　highest　methane　conversion　(88%)　and　syngas　production　rate　(1.8　mol　kgSFO-1　min-1),　but　80　wt　%　SrFeO3-δ-CaO　nanocomposite　has　the　highest　syngas　productivity　(27.3　mol　kgSFO-1);　coke　selectivity　over　the　nanocomposite　with　a　perovskite　mass　fraction　of　0.1　(22%)　is　much　higher　than　that　over　the　others.　Partial　replacement　of　Ca　ions　by　Sr　ions　in　the　CaO　lattice　occurs,　but　substitution　of　Sr　ions　by　Ca　ions　in　SrFeO3-δ,　if　it　occurs,　is　insignificant.　The　predominant　role　of　CaO　is　to　facilitate　SFO　reduction　by　methane　and　improve　its　recyclability.　Besides　that,　calcium　oxide　provides　oxygen　species　that　participate　in　methane　partial　oxidation,　but　this　contribution　is　relatively　small.　In　addition,　the　cracking　activity　of　CaO　is　significantly　suppressed　after　compositing.　These　findings　could　inspire　the　rational　design　of　effective　perovskite　nanocomposites　for　chemical　looping　reforming.　Copyright　©　2020　American　Chemical　Society.