Multi-walled carbon nano-tubes (MWCNTs) were produced by acetylene decomposition on Fe-catalyst in a fluidized bed reactor (0.056 m-ID×1.0m-high) with a sintered metal distributor (40 μm pore size). The Fe-catalysts were tested in decomposition of the different ratios of acetylene, hydrogen and nitrogen at the temperature range of 823-973 K. The physical properties of the carbon nano-tubes were determined by HR-TEM, SEM and Raman spectroscopy. The multi-walled carbon nano-tubes produced from the fluidized bed reactor are sub-aggregates and entangled with each other. The synthesized MWCNTs have outer diameters of a few tens of nanometers at 823-973 K. It has been found that the synthesized CNT agglomerates are in good condition with less amorphous carbon with the reaction time of 30 to 60 minutes from the analyses of Raman Spectra, SEM and TEM, The ratio (ID/IG) of amorphous carbon (ID=1,295 cm-1) and crystalline carbon (IG=1,590 cm-1) range from 1.15 to 1.49.