A　series　of　single-phase　T-structured　NdSrCu1-xCoxO4-delta　with　oxygen　vacancies　and　T＇-structured　Sm1.8Ce0.2Cu1-xCoxO4-delta　(x:　0-0.4)　with　oxygen　excess　were　prepared　using　ultrasound-assisted　citric　acid　complexing　method,　and　characterized　by　means　of　techniques　such　as　thermogravimetric　analysis　and　NO　temperature-programmed　desorption　(NO-TPD).　The　catalytic　activities　of　these　materials　were　evaluated　for　the　decomposition　of　NO.　It　was　found　that　the　NdSrCu1-xCoxO4-delta　catalysts　were　of　oxygen　vacancies　whereas　the　Sm1.8Ce0.2Cu1-xCoxO4-delta　ones　possessed　excessive　oxygen　(i.e.,　over-stoichiometfic　oxygen);　with　a　rise　in　Co　doping　level,　the　oxygen　vacancy　density　of　NdSrCu1-xCoxO4-delta　decreased　while　the　over-stoichiometric　oxygen　amount　of　Sm1.8Ce0.2Cu1-xCoxO4-delta　increased.　The　NO-TPD　results　revealed　that　NO　could　be　activated　much　easier　over　the　oxygen-deficient　perovskite-like　oxides　than　over　the　oxygen-excessive　perovskite-like　oxides,　with　the　NdSrCuO3.702　catalyst　showing　the　best　efficiency　in　activating　NO　molecules.　Under　the　conditions　of　1.0%　NO/helium,　2800　hr(-1),　and　600-900　degrees　C,　the　catalytic　activity　of　NO　decomposition　followed　the　order　of　NdSrCuO3.702　＞　NdSrCu0.8Co0.2O3.736　＞　NdSrCu0.6Co0.4O3.789　＞　Sm1.8Ce0.2Cu0.6Co0.4O4.187　＞　Sm1.8Ce0.2Cu0.8Co0.2O4.104　＞　Sm1.8Ce0.2CuO4.045,　in　concord　with　the　sequence　of　decreasing　oxygen　vacancy　or　oxygen　excess　density.　Based　on　the　results,　we　concluded　that　the　higher　oxygen　vacancy　density　and　the　stronger　Cu3+/Cu2+　redox　ability　of　NdSrCu1-xCoxO4-delta　account　for　the　easier　activation　of　NO　and　consequently　improve　the　catalytic　activity　of　NO　decomposition　over　the　catalysts.