This paper presents a study on the Brazil-nut segregation of binary granularmixtures under vibration by the discrete element method. The ascending velocity of large particles (V-a) and the overall segregation degree (Dsep) are correlated to the vibration velocity amplitude (V-b) and the dimensionless frequency (f(d)). Both D-sep and the average V-a increase linearly with Vb under a given f(d), whilethe coefficient shows a critical change at f(d) =1. V-a conforms to a singlepeak distribution, and the shape parameters of the distribution converge after V-b > 1.7. Both V-a and D-sep can be correlated to (A/ds).(0.5)(fd) universally, where A is amplitude and ds is the small particles size. The increase of the volume fraction of large particles leads to the increase of Dsep and Va, which is probably linked with the increase in granular temperature and the difference between the vibration patterns of large and small particles. (C) 2020 Elsevier B.V. All rights reserved.