In this study, the effect of the electric field in the ionization region and the drift region on the intensities of the signals in ion mobility spectra were studied separately. Two independent power supplies were used to separately change the electric field in the ionization region and the drift region. By keeping the field constant in one region and changing the field strength in another region, the effect of each field on the signals and quality of the ion mobility spectra was evaluated. The range of of the electric field was 500-260, 500-272 (V.cm-1) for the ionization and drift region, respectively. The results of this study showed that increasing the ionization field, only intensifiesthe ion mobility signals, while the increase of the drift field, in addition to increasing the intensity, shifts the peaks to the shorter drift times. Also, as the ionization field increases, the peak intensity ratio of the reactant ions changes, indicating the influence of the ionization field strength on the speed of ions in the reaction region and the change in the residence time of the ion species. Changes in the retention time of ionic species in the ionization region also cause changes in the intensity of the reactant and the product ions. Therefore, the strength of the ionization field is one of the key parameters in the kinetic control of ion-molecule reactions. Since the field strength in the drift region does not affect the ion-molecule reactions, the ion intensity ratios did not change significantly with the drift region change. In this study, the effects of ionization and drift fields on signal resolution were also investigated. In general, the resolution is increased by increasing the ratio of the drift field to the ionization field.