NOVELTY - Preparing catalyst composition having an apparent density of 0.01-0.50 g/ml for the synthesis of carbon nanotube in a high yield of 1000-1800%, comprises: (i) dissolving multi-component metal precursors of catalyst composition in deionized water; (ii) spraying obtained catalytic metal precursor solution into the high temperature reactor by gas atomization method using the air of 2-5 atm pressure; (iii) forming the catalyst composition powder by pyrolysis of gas atomized material at the temperature of 600-1200 degrees C; and (iv) obtaining the catalyst composition powder.    USE - The process is useful for preparing catalyst composition, which is useful for preparing carbon nanotube (all claimed). The carbon nanotube is useful as electrical conductive and strength enhanced filler in polymer composite material, thermal conductive and strength enhanced filler in metal composite, catalyst support of fuel cell, support material of organic process catalyst, storage material for methane and hydrogen gas, electrode material of lithium secondary battery, conductive material of lithium secondary battery, electrode material for high capacity electric double layer capacitor, field emitting material for display, and membrane material.    ADVANTAGE - The process provides catalyst composition with improved productivity in a simple and an economical manner.    DETAILED DESCRIPTION - Preparing catalyst composition having the apparent density of 0.01-0.50 g/ml for the synthesis of carbon nanotube in a high yield of 1000-1800% comprises: (i) dissolving multi-component metal precursors of catalyst composition in de-ionized water; (ii) spraying obtained catalytic metal precursor solution into the high temperature reactor by gas atomization method using the air of 2-5 atm pressure; (iii) forming the catalyst composition powder by pyrolysis of gas atomized material at the temperature of 600-1200 degrees C; and (iv) obtaining the catalyst composition powder, where the catalyst composition comprises (a) main catalyst comprising iron or cobal, (b) aluminum, (c) optional co-catalyst at least one comprising nickel, copper, tin, molybdenum, chromium, manganese, vanadium, tungsten, titanium, silicon, zirconium or yttrium, (d) inactive support of magnesium. INDEPENDENT CLAIMS are included for:    (1) a catalyst composition prepared by the method, where the apparent density of catalyst composition is 0.01-0.50 g/ml; and    (2) a carbon nanotube prepared using the catalyst composition.