A power transmission method for a vehicle, wherein the vehicle includes: an electric generator configured to be driven by a power of an internal combustion engine; a traveling motor configured to drive a driving wheel by an electric power generated by the electric generator; a first power transmission path configured to transmit a power between the traveling motor and the driving wheel; a first meshing clutch mechanism configured to connect or disconnect a power transmission of the first power transmission path; a second power transmission path configured to mechanically transmit the power of the internal combustion engine to the driving wheel; and a second meshing clutch mechanism configured to connect or disconnect a power transmission of the second power transmission path, the driving wheel is driven by the power of the internal combustion engine or a power of the traveling motor, and the traveling motor arranged in the first power transmission path, and the internal combustion engine and the electric generator arranged in the second power transmission path constitute power sources, characterized in that the power transmission method comprises, when switching from one to another of the first power transmission path and the second power transmission path, performing, during a period between a completion of an engagement of one of the first and the second meshing clutch mechanisms (21, 19)- and a release of another of the first and the second meshing clutch mechanisms (19, 21), the period comprising a first period and a second period, at least one of: increasing, in an absolute value, a slope of a torque increase of a power source (3, 2) disposed in the power transmission path (25, 24) corresponding to the one of the meshing clutch mechanisms (21, 19) with respect to a slope of a torque decrease of a power source (2, 3) disposed in the power transmission path (24, 25) corresponding to the another of the meshing clutch mechanisms (19, 21), on a basis of a rotation speed difference (ΔNR) between an input rotation speed and an output rotation speed of the one of the meshing clutch mechanisms (21, 19), in at least a part of the first period, and increasing, in the absolute value, the slope of a torque decrease of the power source (2, 3) disposed in the power transmission path (24, 25) corresponding to the another of the meshing clutch mechanisms (19, 21) with respect to the slope of the torque increase of the power source (3, 2) disposed in the power transmission path (25, 24) corresponding to the one of the meshing clutch mechanisms (21, 19), on a basis of the rotation speed difference (ΔNR) between an input rotation speed and an output rotation speed of the another of the meshing clutch mechanisms (19, 21) in at least a part of the second period. an electric generator configured to be driven by a power of an internal combustion engine; a traveling motor configured to drive a driving wheel by an electric power generated by the electric generator; a first power transmission path configured to transmit a power between the traveling motor and the driving wheel; a first meshing clutch mechanism configured to connect or disconnect a power transmission of the first power transmission path; a second power transmission path configured to mechanically transmit the power of the internal combustion engine to the driving wheel; and a second meshing clutch mechanism configured to connect or disconnect a power transmission of the second power transmission path, the driving wheel is driven by the power of the internal combustion engine or a power of the traveling motor, and the traveling motor arranged in the first power transmission path, and the internal combustion engine and the electric generator arranged in the second power transmission path constitute power sources, characterized in that the power transmission method comprises, when switching from one to another of the first power transmission path and the second power transmission path, performing, during a period between a completion of an engagement of one of the first and the second meshing clutch mechanisms (21, 19)- and a release of another of the first and the second meshing clutch mechanisms (19, 21), the period comprising a first period and a second period, at least one of: increasing, in an absolute value, a slope of a torque increase of a power source (3, 2) disposed in the power transmission path (25, 24) corresponding to the one of the meshing clutch mechanisms (21, 19) with respect to a slope of a torque decrease of a power source (2, 3) disposed in the power transmission path (24, 25) corresponding to the another of the meshing clutch mechanisms (19, 21), on a basis of a rotation speed difference (ΔNR) between an input rotation speed and an output rotation speed of the one of the meshing clutch mechanisms (21, 19), in at least a part of the first period, and increasing, in the absolute value, the slope of a torque decrease of the power source (2, 3) disposed in the power transmission path (24, 25) corresponding to the another of the meshing clutch mechanisms (19, 21) with respect to the slope of the torque increase of the power source (3, 2) disposed in the power transmission path (25, 24) corresponding to the one of the meshing clutch mechanisms (21, 19), on a basis of the rotation speed difference (ΔNR) between an input rotation speed and an output rotation speed of the another of the meshing clutch mechanisms (19, 21) in at least a part of the second period.