La1-xSrxCoO3-delta　(x=0,　0.4)　nanoparticles　have　been　prepared　using　the　citric　acid　complexing-hydrothermal　synthesis　coupled　method　and　citric　acid　complexing　method.　The　physico-chemical　properties　of　these　materials　were　characterized　by　means　of　X-ray　diffraction　(XRD),　high　resolution　scanning　electron　microscopy　(HRSEM),　element　analysis　(EDX),　X-ray　photoelectron　spectroscopic　(XPS),　oxygen　temperature-programmed　desorption　(O-2-TPD),　hydrogen　temperature-programmed　reduction　(H-2-TPR)　as　well　as　surface　area　measurements　and　oxidation　state　titration.　Their　catalytic　performance　was　examined　for　the　total　oxidation　of　ethylacetate　(EA).　It　is　found　that　the　La1-xSrxCoO3-delta　(x=0,　0.4)　catalysts　were　single-phase　and　rhombohedrally-structured　perovskites　and　their　surface　areas　ranged　from　16　to　26　m(2)/g.　The　Sr-doped　sample　derived　from　the　coupled　procedure　was　uniformly　distributed　nanoparticles　with　a　short　rod-shaped　morphology.　The　doping　of　Sr　(i)　enhanced　the　concentrations　of　Co3+　and　oxygen　vacancies,　(ii)　increased　the　amount　of　oxygen　adsorbed　on　the　surface　at　low　temperatures,　(iii)　promoted　the　mobility　of　lattice　oxygen,　and　(iv)　improved　the　properties　of　redox.　The　La0.6Sr0.4CoO2.78　catalyst　prepared　by　the　citric　acid　complexing-hydrothermal　synthesis　coupled　strategy　performed　the　best　in　the　oxidation　of　EA,　furthermore　no　partially　oxidized　products　were　formed.　Based　on　the　above　results,　we　conclude　that　in　addition　to　the　surface　area,　the　catalytic　activity　of　the　perovskite-type　oxide　nanoparticles　was　associated　with　the　structural　defect　(oxygen　vacancy)　concentration　and　redox　ability.