A two-terminal, nonvolatile plastic memory device based on a blend of the conjugated polymer and the soluble multiwall carbon nanotube is fabricated. The conjugated polymer, poly[(9,9-dihexylfluorene-2,7-diyl)-alt-co-(9,9-bis[6(')-(3-methyl-1-imi dazolium-yl)hexyl]fluorene-2,7-diyl)], is a kind of polyelectrolyte containing I- as counterion. As the device is biased on, I- is oxidized to its neutral form electrochemically, and the electrochemically generated iodine dopes the polymer main chain, which increases the conductivity. The nanotubes in the polymer matrix function as an electrode to collect the charge and shorten the path by which the ions diffuse. This hybrid memory cell exhibits good stability and fast response. (c) 2007 The Electrochemical Society.