A power transmission apparatus includes a first input shaft receiving an input torque, second and third input shafts coaxially disposed and selectively connected with the first input shaft, first andsecond torque mediating shafts coaxially disposed with the first input shaft, first and second intermediate shafts and an output shaft disposed in parallel with the first input shaft, a first shiftingsection receiving a torque from the third input shaft and outputting a plurality of first shifted torques, a second shifting section including a first planetary gear set selectively connected with the first input shaft and outputting a plurality of second shifted torques, and a compound shifting section forming an output torque by the input torque and the first and second shifted torques.