Polypyrrole (PPy) nanoparticle was synthesized and coated on a conducting FTO glass to construct PPy counter electrode used in dye-sensitized solar cell (DSSC). Scanning electron microscope images show that PPy with porous and particle diameter in 40-60 nm is covered on the Fro glass uniformly and tightly. Cyclic voltammograms of I-2/I-system measurement reveals that the PPy electrode has smaller charge-transfer resistance and higher electrocatalytic activity for the I-2/I- redox reaction than that Pt electrode does. Overall energy conversion efficiency of the DSSC with the PPy counter electrode reaches 7.66%, which is higher (11%) than that of the DSSC with Pt counter electrode. The excellent photoelectric properties, simple preparation procedure and inexpensive cost allow the PPy electrode to be a credible alternative used in DSSCs. (C) 2008 Published by Elsevier B.V.