A planetary gear train of an automatic transmission for a vehicle may include: an input shaft receiving torque of an engine; an output shaft outputting torque and disposed in parallel with the input shaft; a compound planetary gear set having first, second, third, and fourth rotation elements and disposed at a radial external side of the input shaft; a simple planetary gear set having fifth, sixth, and seventh rotation elements and disposed at a radial external side of the output shaft; first to seventh shafts, each fixedly connected at least one among the first to seventh rotation elements; an eighth shaft selectively connectable to the input shaft; and two transfer gear sets operably connecting at least one shaft among the first to eighth shafts to another shaft.