PURPOSE: To realize the gear ratio suitable for a transmission having forward six speed or more by combinating a parallel shaft-type speed change mechanism having more than two pairs of gear pairs with a planetary gear mechanism.

CONSTITUTION: More than one output elements 24, 26 of a parallel shaft-type speed change mechanism are selectively connected to two elements of a planetary gear mechanism 14 according to the operating state of clutches C1 to C4 and brakes B1, B2. For exmaple, an internal gear 18 is always connected to an output shaft 12, and any output of two pairs of gears 24, 28 and 26, 32 is input into a carrier 22, and a sun gear 16 is fixed by the brake B1. Since there are more than one output elements 24, 26 of the parallel shaft-type speed change mechanism and they are input in the planetary gear mechanism 14, the forward six speed can be obtained when two pairs of gears are used by these combination. Moreover, since the rotational ratio of the gears of the parallel shaft-type speed change mechanism has the larger degree of freedom in comparison with the planetary gear mechanism, the preferable stage ratio can be obtained as a transmission having the forward six speed or more.