In this study, polymerization of 3,4-ethylenedioxy-thiophene (EDOT) was started in aqueous solutions containing different concentrations of aniline-2sulfonic acid. The pH of the aqueous solution and the reaction time was also varied to investigate their effect on the degree of polymerization. The obtained polymers were characterized by scanning electron microscopy (SEM), and the experiment data are analyzed by ANOVA analysis. The results observed after the reaction mixtures were centrifuged for different periods of time were combined with two-factor ANOVA analysis to evaluate the main and side interaction effects on the degree of polymerization.