The crystal structure and infrared absorption spectra of nanocrystallineDy1-xSrxCoO3-y (0.0≤x≤1.0) were studied. The results show that the latttice paratmeters werehigger than microcrystallines. The mixed oxides crystallized in orthorhombic (0.0≤x≤0.5) ortetragonal system (0.6≤x≤0.9) or hexagonal system (x=1.0 ). With symmetry centre of crystalstructure variation, the spectra bands of nanocrystallines were fissioned. The infrarea absorptionspectra of nanocrystallines appeared as quantum size effect.