Theoretical analysis and molecular dynamics simulations are presented to study the mechanical behaviors of Carbon nanoscrolls (CNSs). The study shows that a graphene sheet can rapidly self-scroll onto a carbon nanotube. The van der Waals interaction between the graphene sheet and the nanotube is the driving force of self-assemble process. During self-assemble process, the van der Waals energy of the system is partially balanced with the bending energy of the graphene walls and partially converted to the kinetic energy of the CNS. If a new graphene sheet is attached to the nanoscroll with end to end joint, the new graphene will self-assemble into the CNS and the spontaneously formed CNSs will rotate around the nanotube. If a new graphene sheet is attached the CNS with lap joint, the new graphene sheet will self-scroll onto the CNS and the spontaneously formed CNSs will oscillate around the nanotube with high frequency.;Theoretical analysis and molecular dynamics simulations are presented to study the mechanical behaviors of Carbon nanoscrolls (CNSs). The study shows that a graphene sheet can rapidly self-scroll onto a carbon nanotube. The van der Waals interaction between the graphene sheet and the nanotube is the driving force of self-assemble process. During self-assemble process, the van der Waals energy of the system is partially balanced with the bending energy of the graphene walls and partially converted to the kinetic energy of the CNS. If a new graphene sheet is attached to the nanoscroll with end to end joint, the new graphene will self-assemble into the CNS and the spontaneously formed CNSs will rotate around the nanotube. If a new graphene sheet is attached the CNS with lap joint, the new graphene sheet will self-scroll onto the CNS and the spontaneously formed CNSs will oscillate around the nanotube with high frequency.