Conductive　micro/nano-structural　poly(N-ethylaniline-co-aniline)　(PNAAN)　copolymers　were　synthesized　via　unstirred　polymerization　of　N-ethylaniline　(NA)　and　aniline　(AN)　with　ammonium　peroxydisulfate　as　an　oxidant.　Morphology,　structure　and　electrical　conductivity　of　the　copolymers　were　characterized　by　means　of　SEM,　TEM,　FT-IR,　UV-vis,　and　four-probe　techniques.　It　is　found　that　the　structure,　morphology　and　properties　of　the　copolymer　strongly　depend　on　the　NA/AN　molar　ratio.　PNAAN(10/90)　copolymer　nanofibers　in　diameters　of　139　nm~186　nm　and　lengths　up　to　4.2　μm　were　prepared　with　APS/comonomer　molar　ratio　of　1.0,　whereas　PNAAN(50/50)　copolymer　spheres　with　smooth　surface　(1.3　μm~3.6　μm　in　outer　diameter)　were　produced　during　the　same　above-mentioned　polymerization　conditions.　While　the　PNAAN　(90/10)　copolymer　self-assembled　hollow　microspheres　with　coarse　surface　(4.45　μm　in　outer　diameter)　were　obtained.　The　SEM　image　reveals　that　the　PNAAN(50/50)　copolymer　spheres　are　constructed　with　their　own　nanofibers　by　self-assembly　process.　The　as-synthesized　PNAAN　copolymers　possess　good　room-temperature　electroconductivity　and　solubility.