NOVELTY - Strontium nitrate aqueous solution (a), polyvinyl alcohol aqueous solution (b) (4-32 g/L), potassium hydroxide (c), titanium oxyhydroxide (d) and de-ionized water are stir-mixed for 10 minutes in a reaction kettle having polytetrafluoroethylene liner, to obtain precursor paste. The reaction kettle is then sealed by a stainless steel cover, and subjected to hydro-thermal treatment at 100-150 degrees C for 48-96 hours. The resulting mixture is filtered, washed by de-ionized water, and dried to obtain one-dimensional structural strontium titanate nanopowder.    USE - Preparation of one-dimensional structural strontium titanate nanopowder used in photocatalyst, microelectronic device, optoelectronic device, storage device, oxygen sensor and solar cell.    ADVANTAGE - The one-dimensional structural strontium titanate nanopowder having large specific surface area is economically prepared with high productivity, by simple process.    DETAILED DESCRIPTION - A tetra butyl titanate is dissolved in absolute ethyl alcohol. The concentration of tetravalent titanium ion in the obtained solution is then adjusted to 0.1-0.5 mol/L. 30 mass% Ammonia solution (1-2 ml) is added and stirred. The deposited substance is filtered, and washed to obtain titanium oxyhydroxide (d). Strontium nitrate aqueous solution (a) having strontium ion concentration of 0.05-0.5 mol/L formed by dissolving strontium nitrate in de-ionized water, polyvinyl alcohol aqueous solution (b) (4-32 g/L) formed by dissolving polyvinyl alcohol in de-ionized water, potassium hydroxide (c) and titanium oxyhydroxide are added to a reaction kettle having polytetrafluoroethylene liner. The volume of reaction mixture in reaction kettle is adjusted to 70-90% of the volume of reaction kettle by adding de-ionized water, and stirred for 10 minutes to obtain precursor paste. The reaction kettle is then sealed by a stainless steel cover. The reaction mixture in the sealed kettle is subjected to hydro-thermal treatment at 100-150 degrees C for 48-96 hours. The resulting mixture is filtered, washed by de-ionized water, and dried to obtain one-dimensional structural strontium titanate nanopowder. The content of titanium, strontium and potassium hydroxide contained in the reaction mixture is is 0.02-0.1 mol/L, 0.01-0.1 mol/L and 0.2-1 mol/L, respectively. The molar ratio of strontium and titanium is 0.5-1.0. The usage amount polyvinyl alcohol is 1-8 g/L. The one-dimensional structure comprises strontium titanate nanowires and a branch crystalline structure composed of nanowires.