Poly(2,5-dipropargyloxy-1,4-phenylenevinylene) (PDPPV) and its copolymers were prepared as thin films via the organic-soluble and water-soluble precursor routes. Elimination and crosslinking reactions could be controlled by the temperature. Crosslinked PDPPV is stable up to 450 degrees C. The conductivity values of undrawn and drawn FeCl3-doped PDPPV films are 5.0 x 10(-2) and 2.0 x 10(-1) S . cm(-1), respectively. The third-order nonlinear optical susceptibility, chi((3)), for the PDPPV film was investigated by degenerate four-wave mixing (DFWM) technique at 602 nm wavelength, and found to be 2.3 x 10(-10) esu.