NOVELTY - Synthesis of high dispersed spherical yttrium or niobium doped lithium titanate oxide, comprises diluting titanium tetrachloride with titanium(IV) oxychloride, adding yttrium(III) chloride or niobium(V) chloride to titanium, forming a complex salt by dissolving hydroxy propyl cellulose and polyethylene glycol in a solvent, synthesizing a titanium precursor by adding an aqueous ammonia solution, preparing yttrium or niobium doped titanium dioxide powder by heat-treating the synthetic product, and mixing yttrium or niobium doped titanium dioxide powder with lithium hydroxide monohydrate.    USE - The method is useful for synthesizing high dispersed spherical yttrium or niobium doped lithium titanate oxide (claimed), which is useful for fabricating a cathode of a lithium ion secondary battery such as storage devices for a hybrid electric vehicle or a plug-in hybrid/electric vehicle.    ADVANTAGE - The high dispersed spherical yttrium or niobium doped lithium titanate oxide fabricates the cathode of the lithium ion secondary battery with improved electrochemical properties, capacity, power output and stability.    DETAILED DESCRIPTION - Synthesis of high dispersed spherical yttrium or niobium doped lithium titanate oxide, comprises diluting titanium tetrachloride with titanium(IV) oxychloride, adding yttrium(III) chloride or niobium(V) chloride at 0.1-2 mol.% to titanium, forming a complex salt by dissolving to put hydroxy propyl cellulose and polyethylene glycol in a solvent, where the hydroxy propyl cellulose is a complexing agent and a dispersing agent, and the polyethylene glycol is a dispersing agent, synthesizing a titanium precursor by adding an aqueous ammonia solution, preparing yttrium or niobium doped titanium dioxide powder by heat-treating the synthetic product in a temperature of 500-700 degrees C, and mixing yttrium or niobium doped titanium dioxide powder with lithium hydroxide monohydrate and then heat-treating the mixture in a temperature of 800-900 degrees C. An INDEPENDENT CLAIM is included for the high dispersed spherical yttrium or niobium doped lithium titanate oxide having a structure of formula (Li4Ti5-xMxO12).    M = Y or Nb; and    x = 0.005-0.1.