The investigated samples were of cellulose nitrate CA-80-15. The de conductivity (sigma) and the dielectric permittivity decreased with increasing time of annealing. The activation energy is 0.46 eV in a temperature range from 298 to 385 K. The thermally stimulated current (TSC), J(D), was measured. The maximum value of the TSC (J(m)) increases with increasing the rate of heating and shifts slightly toward higher values of temperature. The activation energy (0.25 eV) is independent of the variation of the rate of heating. In addition, the peak positions for the constant rate of heating were unaffected by increasing the polarization time, but the maximum value of the current increases and the activation energy decreases. The dipolar relaxation time was calculated theoretically and studied as a function of temperature.