We present dynamic folding pathway models of a-helix and P-hairpin structures at atomistic details by using the action-derived molecular dynamics method. The present formulation is free from common assumptions widely used in molecular dynamics such as high temperature simulations, a choice of order parameter set, an arbitrary identification of the folded configuration, or an exponential kinetics. The present dynamic folding pathway models for both helix and hairpin formations are consistent with experimental data. (c) 2005 Elsevier B.V. All rights reserved.