The semiempirical self-consistent field molecular orbital calculation MNDO-PM3 method was utilized to obtain the electronic structural parameters of 13 p-aminobenzoates. Stepwise multiple regression analyses were then utilized to generate quantitative structure-activity relationships between the percutaneous fluxes or permeability coefficients and the electronic structural parameters. The results showed that both the percutaneous fluxes and permeability coefficients were well correlated parabolically with the electrophilic superdelocalizabilities summed over all atoms (sigma SE) or the sum of the absolute values of the net atomic charges (sigma Q). Significant correlations were observed between sigma SE or sigma Q and the octanol/water partition coefficients or the molecular volumes.