Photoconductive properties of the composite devices made up of cadmium selenide nanocrystals and polymer poly[2-methoxy-5-(2'-ethylhexyloxy-p-phenylenevinylene)] (MEH-PPV) were investigated. The photocurrent action spectrum for a nanocomposite device corresponded to the absorption of MEH-PPV and CdSe nanocrystals, indicating that the absorption of the CdSe nanocrystals and MEH-PPV contributed to the photocurrent. The photocurrent was attributed to the exciton dissociation and charge transfer between the interface of CdSe nanocrystals and MEH-PPV. The photocurrent action spectra of the nanocomposite device was wider than that of the pure MEH-PPV device, and the photocurrent was enhanced in comparison with the pure MEH-PPV device due to the introduction of CdSe nanocrystals.