Poly(2-methoxy-5-(2-(4-nitrophenyl)ethenyl)-1,4-phenylenevinylene) (PMNEPV) and a series of copolymers (poly(MNEPV-co-PV)) containing varying amounts of 1,4-phenylenevinylene (PV) units have been synthesized via soluble precursor polyelectrolytes. These polymers possess a unique structural feature in which the electron-donating methoxy groups are located on the phenylene rings along the main chain whereas the electron-attracting nitro groups are attached to the side chain styryl substituents. The u.v.-vis. spectra of PMNEPV and the poly(MNEPV-co-PV)s revealed two major absorptions arising from pi-pi(*) transitions of the two pi-electron systems : the first peak is due to the pi-system in the 4-methoxy-4’-nitrostilbene moiety and the second due to the K-system in the backbone. The maximum electrical conductivity of FeCl3- or I-2-doped copolymers increased rapidly initially with the level of MNEPV unit followed by a gradual decrease when the content of MNEPV unit was > 7 mol%. The dependence of the electrical conductivity of the present series of copolymers, when doped either with I-2 or FeCl3, is almost the same as that observed earlier by us for poly(2-methoxy-5-(2-phenylethenyl)-1,4-phenylenevinylene) and its copolymers containing the PV unit.