A vehicular automatic transmission is provided with a reduction planetary gear for reducing and outputting an inputted rotation of an input shaft, first and third clutches for enabling the transmission of a reduced rotation reduced through the reduction planetary gear, a planetary gear unit having second and third sun gears to which the reduced rotation is transmitted by the first and third clutches and a fourth clutch for enabling the transmission of the inputted rotation to the second sun gear. The fourth clutch is linked to the second sun gear of the planetary gear unit via output side members, i.e., a clutch drum and a link member, of the third clutch to commonly use as the output side members. Thereby, the automatic transmission may be compactly built.