A vehicle power transmission apparatus comprising: a planetary gear mechanism on a power transmission path, a power from a power source being transmitted to the power transmission path, the planetary gear mechanism including rotational elements, the rotational elements including a rotational element configured to transmit a power to an output shaft, wherein a meshing change operation of a meshing mechanism (62H, 62L, 63, 64, 66) switches the rotational element configured to transmit the power to the output shaft so as to change a gear ratio on the power transmission path, characterized in that the planetary gear mechanism includes: a sun gear (61 S) coupled to an input shaft to rotate integrally, a ring gear concentrically disposed with the sun gear (61 S), a plurality of pinion gears engaging the sun gear (61 S) and the ring gear and a planetary carrier rotatably and revolvably supporting the plurality of pinion gears; the meshing mechanism (62H, 62L, 63, 64, 66) includes a first sleeve configured to be switched between: a first position where the output shaft is connected to the input shaft but not connected to the planetary carrier (61 CA) so that the input shaft serves as the rotational element configured to transmit the power to the output shaft; and a second position where the output shaft is connected to the planetary carrier (61 CA) but not connected to the input shaft so that the planetary carrier (61 CA) serves as the rotational element configured to transmit the power to the output shaft; a brake unit configured to selectively secure the ring gear of the planetary gear mechanism to a housing; and an electric machine configured to transmit the power to the planetary carrier of the planetary gear mechanism, wherein when the meshing change operation of the first sleeve switches the rotational element configured to transmit the power to the output shaft, the apparatus performs a synchronous operation where the brake unit is released to allow the ring gear to rotate and the power from the electric machine rotates the planetary carrier to set a rotational speed at an input shaft side close to a rotational speed at an output shaft side, and, after the switching operation, the apparatus engages the brake unit to stop rotation of the ring gear. a planetary gear mechanism on a power transmission path, a power from a power source being transmitted to the power transmission path, the planetary gear mechanism including rotational elements, the rotational elements including a rotational element configured to transmit a power to an output shaft, wherein a meshing change operation of a meshing mechanism (62H, 62L, 63, 64, 66) switches the rotational element configured to transmit the power to the output shaft so as to change a gear ratio on the power transmission path, the planetary gear mechanism including rotational elements, the rotational elements including a rotational element configured to transmit a power to an output shaft, wherein a meshing change operation of a meshing mechanism (62H, 62L, 63, 64, 66) switches the rotational element configured to transmit the power to the output shaft so as to change a gear ratio on the power transmission path, characterized in that the planetary gear mechanism includes: a sun gear (61 S) coupled to an input shaft to rotate integrally, a ring gear concentrically disposed with the sun gear (61 S), a plurality of pinion gears engaging the sun gear (61 S) and the ring gear and a planetary carrier rotatably and revolvably supporting the plurality of pinion gears; the meshing mechanism (62H, 62L, 63, 64, 66) includes a first sleeve configured to be switched between: a first position where the output shaft is connected to the input shaft but not connected to the planetary carrier (61 CA) so that the input shaft serves as the rotational element configured to transmit the power to the output shaft; and a second position where the output shaft is connected to the planetary carrier (61 CA) but not connected to the input shaft so that the planetary carrier (61 CA) serves as the rotational element configured to transmit the power to the output shaft; a first position where the output shaft is connected to the input shaft but not connected to the planetary carrier (61 CA) so that the input shaft serves as the rotational element configured to transmit the power to the output shaft; and a second position where the output shaft is connected to the planetary carrier (61 CA) but not connected to the input shaft so that the planetary carrier (61 CA) serves as the rotational element configured to transmit the power to the output shaft; a brake unit configured to selectively secure the ring gear of the planetary gear mechanism to a housing; and an electric machine configured to transmit the power to the planetary carrier of the planetary gear mechanism, wherein when the meshing change operation of the first sleeve switches the rotational element configured to transmit the power to the output shaft, the apparatus performs a synchronous operation where the brake unit is released to allow the ring gear to rotate and the power from the electric machine rotates the planetary carrier to set a rotational speed at an input shaft side close to a rotational speed at an output shaft side, and, after the switching operation, the apparatus engages the brake unit to stop rotation of the ring gear.