A method of producing a positive electrode composition for a non-aqueous secondary battery is provided. The method includes heat-treating titanium boride particles at a temperature in a range of 150° C. to 300° C. under an oxygen-containing atmosphere to obtain heat-treated particles and mixing the heat-treated particles with a positive electrode active material comprising lithium transition metal complex oxide particles that comprise nickel in a composition and have a layered structure such that a content of the heat-treated particles relative to the lithium transition metal complex oxide particles is less than or equal to 1.5 mol % in titanium equivalent terms.