A new method is reported to produce linear carbon allotrope from the pyrolysis of starch catalyzed by Fe. The pyrolytic product termed as carbon atom wires (CAW) is composed of winding lines with the diameter around 2.0 Angstrom, indicated by magnified HRTEM images. The experimental results of UN and Raman spectra revealed a conjugated sequence of cumulated double bonds (=C=C=)(n) presented in the hexane extract of CAW. Arguments about the sp hybridization bonding structure of CAW can also be supported by EELS and FT-IR measurements. (C) 2004 Elsevier B.V. All rights reserved.