We report our recent study on processes of decomposition of tripropylamine (TPA) molecules in the channels of AlPO-5 (AFI) and Co-incorporated AlPO-5 (CoAPO-5) zeolite crystals, by means of Fourier transform Infrared (FTIR) spectra and thermogravimetry (TG) techniques. In comparison with pure AlPO-5 crystals, the carbonization temperature of TPA molecules inside the channels of Co-AFI crystals is notably decreased; indicating that Co atoms incorporated in the AFI framework plays an important catalyst role. These incorporated Co atoms are also favorable to the formation of the 0.4 nm single-walled carbon nanotubes (SWNTs) in the channels, characterized by a significant decrease in nanotubes formation energy. The resulting SWNTs have higher filling density in the channels than that fabricated without catalyst Co. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.