SUMMARYNanocomposites are potential materials that can be used to improve the flame resistance of polymers without the need for halogen-based flame retardants. However, the nanocomposites cannot be used as the only raw material to produce final products as they are too expensive compared with low-cost commodity plastics. Therefore, some types of polyolefin-based floor sheet laminated with nanocomposites film were prepared for the cone calorimetric study to determine the suitable nanocomposites laminated structure for flame resistance. This study found that the polyolefin-based floor sheet laminated with 200 m Nylon-6/montmorillonite nanocomposites film on the surface can reduce the HRR max and the S max significantly; other types of nanocomposites film-laminated floor sheet were not able to reduce their flame resistance in comparison with the normal Nylon-6 film-laminated floor sheet. Meanwhile, based on the gas barrier performance, the higher aspect ratio of clay is assumed to contribute to the higher flame resistance of nanocomposites. Thus, the polyolefin-based floor sheet laminated with Nylon-6/sericite nanocomposites film on the surface was also prepared and examined in the cone calorimetric study. However, the Nylon-6/sericite nanocomposites film surface-laminated floor sheet did not cause a significant reduction in the HRR max and S max compared with the Nylon-6/montmorillonite nanocomposites film surface-laminated floor sheet. The grade determined according to the standard fire test and the mechanical properties of the Nylon-6/montmorillonite nanocomposites film surface-laminated floor sheet satisfied the requirements for floor sheets for Japanese railway vehicles.