Disclosed herein is a small particle oxide powder for dielectrics. The oxide powder has a perovskite structure, an average particle diameter [D50(.mu.m)] of 0.3 .mu.m or less, a particle size distribution of the average particle diameter within 3%, a particle size distribution satisfying a condition D99/D50<2.5, a content of OH.sup.- groups of 0.2 wt % and a C/A axial ratio of 1.006 or more. A method of manufacturing the oxide powder comprises the steps of mixing TiO.sub.2 particles and a compound solved with at least one element represented by A of the perovskite structure of ABO.sub.3; drying and pulverizing the mixture of TiO.sub.2 and the compound; calcining the pulverized mixture; adding the oxide containing the elements of the site A to the coated TiO.sub.2 particles and wet-mixing, drying and pulverizing; primarily calcining and pulverizing the pulverized powder under vacuum; and secondarily calcining and pulverizing the powder.