We have successfully demonstrated the multiwall carbon nanotube (MWCNT) based field emission cathode fabricated on highly porous, flexible and conductive carbon fiber (CF) sheet without damage of CF sheet by chemical vapor deposition. CF sheet was composed of thin fibers with diameter of about 3 pm prepared by electrospray deposition. Well aligned MWCNTs grown on, or well anchored to. the flexible CF sheet was confirmed by transmission electron microscope. The field enhancement factor for MWCNT emitter fabricated on CF sheet was about 14,000 and 1.6 times higher than that of MWCNT emitter fabricated on Si substrate. Scanning electron microscopy image indicates that the electron emission occurred from the MWCNT field emitter arrays grown on carbon fibers not only at surface but also under layers in CF sheet. Field emission measurements revealed that this flexible MWCNT field emitter array has a great potential for the flexible field emission displays. (C) 2008 Elsevier B.V. All rights reserved.