To reduce impurities of a radioactive nuclide to a permissible level in the case producing TiO2 by a chlorination method by carrying out specific treatment prior to reduction and baking, in a method for selecting out titanium- containing raw materials comprising reducing and baking a titanium-containing raw material and leaching the treated raw material with an inorganic acid.

This method for selecting out titanium-containing raw materials comprises reducing and baking a titanium-containing raw material which is preferably ilmenite, leucoxene, high-grade titanium ore, titanium slag or synthetic rutile and leaching the treated raw material with an inorganic acid. In the selecting out method, the titanium-containing material, preferably having about 200 or more US mesh is subjected to heat treatment in an aqueous solution of an inorganic acid, preferably hydrochloric acid. The heat treatment is preferably carried out in the concentration of the inorganic acid of about 8 to about 30wt.% under about 1-5 atmospheric pressure at about 100 to <160°C for at least one hr.