The results of electron paramagnetic resonance (EPR) experiments are reported for chemically synthesized polypyrroles soluble in organic solvents, which have different doping levels. Pauli susceptibility $({\ensuremath{\chi}}^{P})$ and the density of states $[{D(E}_{F})]$ are obtained from the temperature dependence of magnetic susceptibility. The ${\ensuremath{\chi}}^{P}$ and the ${D(E}_{F})$ increase as the doping level increases, which indicates that the system becomes more highly conducting. The electron spin-lattice relaxation time ${(T}_{1})$ is measured by using saturation methods. The ${T}_{1}$ decreases with increasing doping level at room temperature. This implies that the spin-lattice interaction easily occurs in the sample with the high concentration of dopants. The EPR linewidth $(\ensuremath{\Delta}H)$ linearly increases as temperature increases from 100 K to room temperature. We use a Korringa relaxation rate to account for the temperature dependence of the $\ensuremath{\Delta}H.$