In an attempt to examine dynamic involvement of multiple brain regions in the auditory selective attention process, negative difference wave (Nd) generators were assessed using a high-resolution EEG system (128ch) and scalp current density (SCD) analysis. Ten normal volunteers participated in the study. Event-related potentials were recorded during a selective attention task. Sequential SCD mappings revealed that current sinks were located in the bilateral temporal regions at 160 ms subsequent to the onset of stimuli, shifting the dipole orientation more tangentially to the scalp at around 220 ms. Moreover, a current sink was demonstrated in the midfrontal region at around 320 ms. These findings confirm that different cortical regions are sequentially involved in the auditory selective attention process.