The Potts and Guy's model for skin permeability, log P = alpha log K - beta MV + delta where P is the permeability coefficient of a compound from aqueous solution through human skin in vitro, K and MV are octanol-water partition coefficient and molecular volume of the compound respectively, and alpha, beta, delta are constants, is examined for a data set of 53 miscellaneous compounds. The model will result in over-estimation for penetrants having higher hydrogen-bond donor activity and underestimation for penetrants having no hydrogen-bond donor. A predictive algorithm for skin permeability including the effects of hydrogen-bond on diffusivity is proposed: log P = alpha log K - beta MV - gamma Hb + delta where Hb is the descriptor of hydrogen-bonding capacity of penetrants and gamma is a constant. The calculated log P values from the latter model are in good accordance with respective experimental ones for the data set.