NOVELTY - Modified lithium vanadium phosphate carbon composite contains lithium vanadium phosphate carbon composite particles consisting of lithium vanadium phosphate and electroconductive carbon material. Lattice constant of C axis is 12.038-12. curved left arrow 042 Angstrom .    USE - Modified lithium vanadium phosphate carbon composite for lithium secondary battery positive electrode active material, used in lithium secondary battery for household electronic appliances, electronic devices, notebook personal computer, laptop computer, pocket word processor, mobile telephone, cordless phone unit, portable compact disk (CD) player, radio, liquid crystal television, backup power supply, electric shaver, memory card, motor vehicle, electric vehicle, game machine device, and electric tool.    ADVANTAGE - Lithium secondary battery obtained has outstanding charging/discharging cycling characteristics.    DETAILED DESCRIPTION - Modified lithium vanadium phosphate carbon composite contains lithium vanadium phosphate carbon composite particles consisting of lithium vanadium phosphate of formula LixVy(PO4)3 (1) and electroconductive carbon material. Lattice constant of C axis is 12.038-12.042 Angstrom .    x=2.5-3.5; and    y=1.8-2.2.    INDEPENDENT CLAIMS are included for:    (1) modification of lithium vanadium phosphate carbon composite which involves mixing precursor of penta- or tetravalent lithium vanadium compound, phosphorus source, calcium compound, and electroconductive carbon material in aqueous medium to obtain raw material liquid mixture, heating the raw material liquid mixture, performing precipitation reaction, wet-grinding the reaction liquid which contains precipitation product using media mill to obtain slurry, spray-drying to obtain reaction precursor, and baking at 600-1300 degrees C in inert gas atmosphere or reducing environment;    (2) manufacturing method of modified lithium vanadium phosphate carbon composite which involves modification of lithium vanadium phosphate carbon composite;    (3) lithium secondary battery positive electrode active material comprising modified lithium vanadium phosphate carbon composite; and    (4) lithium secondary battery comprising lithium secondary battery positive electrode active material.