New photoconductive materials are explored from three groups of polyacetylenes: poly-(phenylacetylenes) s[HCdC(C 6 H 5 -p-R)] n s, poly(3-thienylacetylenes) s[HCdC(3-C 4 H 2 S-β-R′)] n s, and poly(1-alkynes) s{HCdC[(CH 2 ) m R′′]} n s, where R ) CH 3 (2), CO 2 (CH 2 ) 6 OCO-Biph-OC 7 H 15 (Biph ) 4,4′-biphenylyl; 3); R′ ) Si(CH 3 ) 3 (4), Br (5); and R′′ ) CO 2 (CH 2 ) 6 OCO-Biph-OC 9 H 19 (m ) 2; 6), 9-carbazolyl (m ) 3; 7) and OCO-Biph-OC 7 H 15 (m ) 9; 8). Photoconduction in the polyacetylenes under illumination of visible light is investigated using photoinduced xerographic discharge technique. In the pure (undoped) state, all the polyacetylenes except 5 show higher photosensitivity than do poly(phenylacetylene) (R ) H; 1), a well-studied photoconducting polyacetylene, and poly(9-vinylcarbazole), the bestknown photoconducting vinyl polymer. Among the polyacetylenes, photoconduction performance of the polymers with electron-donating and/or hole-transporting moieties is superior to those with electron-accepting ones. The liquid crystalline polymer 6 exhibits very high photosensitivity, probably due to the formation of crystalline aggregates of its mesogenic pendants induced by the thermal treatment in the photoreceptor preparation process. C 60 acts as a photoconductivity enhancer when doped to amorphous 3, but functions as a crystallinity-breaking plasticizer when doped to liquid crystalline 6, leading to a large decrease in photoconductivity. While 3 shows a low photosensitivity (2.8 × 10 -3 lx -1 s -1 ) to a 573 nm light in the undoped state, doping with I 2 and sensitization with crystal violet (CV) dramatically increase its photosensitivity (up to 41.2 × 10 -3 lx -1 s -1 ). The CV-sensitized 4 exhibits high photoconductivity in the near-infrared spectral region, which may find technological applications in the digital photoimaging systems.