The process of particle breakage affects the mechanical characteristics of rockfill materials, which are used extensively in geotechnical projects. Therefore, in this research, a series of large-scale triaxial tests on angular rockfills were conducted to investigate the particle breakage behavior using five different methods ("Marsal", "Lee & Farhoomand", "Hardin", "Lade & Yamamuro" and "Indraratna"). The relation between the particle breakage and each parameter, including "confining pressure", "maximum deviatoric stress", "maximum principal stress ratio", "maximum dilatancy angle", "peak friction angle" and "D-10, D-15 and D-50" was investigated. Moreover, in order to present a more comprehensive and simplified description of the breakage factor variations, the parameters "Los Angeles abrasion", "point load strength index" and "changes in C-u and C-c coefficients" were modified to one parameter named "J". The results indicated that among five breakage factors, Marsal's index best described the breakage behavior of rockfill materials. (c) 2020 Elsevier B.V. All rights reserved.