Nanolayered materials exhibit unique plastic deformation behavior, i.e., a bulk-like to small-scale plasticity transition and a scaling behavior of extremely small activation volume (V-not asymptotic to < 10b(3)) with intrinsic size. This unusual plastic transition phenomenon likely stems from the dislocations respectively emit from interfaces and Frank-Read-type bulk sources below and above a critical intrinsic size similar to 20 nm. We quantitatively capture the scaling relationship between strain rate sensitivity and intrinsic size by a phenomenological model based on the Orowan-Frank-Read process. (C) 2014 Elsevier B. V. All rights reserved.