The high concentration emulsion polymerization of 3,4-ethylenedioxythiophene in the presence of sodium salt of 2-naphthalenesulfonic acid as dopant and emulsifier and ferrum(III) sulfate as oxidant is described. By means of IR-spectroscopy it was shown that the resulting polymer is poly(3,4-ethylenedioxythiophene) and by means of transmittance electron microscopy it was demonstrated that it is characterized by the morphology of shapeless flat formations. It was found out that the conductivity of poly(3,4-ethylenedioxythiophene) obtained by this method depends on the amount of washing water passing through the maximal conductivity value 160 S/cm. The influence of heat treatment at 125C of poly(3,4-ethylenedioxythiophene on its conductivity and morphology was studied. It was shown that the initial conductivity of poly(3,4-ethylenedioxythiophene) considerably influences the conductivity of the heat treated poly(3,4-ethylenedioxythiophene). The heating of poly(3,4-ethylenedioxythiophene) with low conductivity leads to the decrease of its conductivity while the heating of the poly(3,4-ethylenedioxythiophene) with maximal conductivity of 160 S/cm leads to increase of its conductivity up to several thousands S/cm. Transmittance electron microscopy shows that the morphology of poly(3,4-ethylenedioxythiophene) with conductivity of several S/cm are monocrystalls.