Breakage behavior under impact of two different types of biomass resources (poplar and corn stover) is characterized, taking into account the influences of the impact energy, of the number of impacts, of the input particle size and of the material properties itself. Within corn stover, two fractions showed different breakage behavior and they were analyzed separately: corn cob and corn stalk and leaves. Biomass resources present several inherent complexities such as its fibrous non-brittle behavior and the non-spherical shape of their particles. Mastercurve formulation for breakage probability (S) based on the resistance of the particles against fracture (f(mat)) and on the mass specific energy which a particle can absorb without fracture (W-m,W- min) was obtained. Moreover, a new formulation of the new particle population generated after the impact (breakage function, B) was developed incorporating two new material parameters (gamma and alpha) to a power law function. Corn cob showed much higher threshold energy for fracture (W-m,W- min) than corn stalk/leaves and poplar. Furthermore, corn cob presented the highest values of gamma and alpha that represent coarser new particle generation. Corn stalk/leaves and poplar showed more similar material parameters in comparison to corn cob. (C) 2014 Elsevier B.V. All rights reserved.