In this article, the interlayer shear effects on vibrational behavior of bilayer graphene (BG) are studied by using the molecular mechanics (MM) simulation. Investigation on mechanical behavior of graphenes has recently attracted because of their excellent properties. MM simulation is exploited for modeling of covalent bond in the plane of graphene layers and they are modeled as space-frame structures. The interaction between two layers is modeled by Lennard–Jones potential for not only two apposite atoms but also for all adjacent atoms. The frequencies and mode shapes for cantilever and bridged bilayer graphene as well as monolayer graphene (MG) are obtained by a finite element approach. Results show that the interlayer shear interaction has considerable effect on vibrational behavior of BG and increases the natural frequencies, because existence of horizontal forces (shear forces) that prevent the lateral displacements. It can be seen that the interaction between two layers are more considerable in second mode because the curvature and variation of displacement are higher in second mode. Also it can be found that changing of mode shapes has considerable effect on shear interaction.