The present invention provides a layout of a power transmission device for a hybrid vehicle which provides a high damping force a high damping force against engine fluctuation at low RPM operation by an engineFor this, the preset invention provides a power transmission device for a hybrid vehicle, in which an automatic transmission having an input shaft, a motor, an engine clutch, a flywheel, and an engine having an output shaft connected to a crank shaft of the engine are directly connected to the same axis, the power transmission device including: a motor support shaft, the outer end of which is supported by a motor rotor and the inner end of which extends toward the boundary between the output shaft of the engine and the input shaft of the automatic transmission; a motor housing arranged so as to surround the outer circumference and the left side surface of the motor rotor; a torsion damper disposed between the left side end of the motor housing and the motor rotor; an engine clutch, disposed between the left side end of the motor housing and the left side surface of the inner end of the motor support shaft, for power transmission between the output shaft of the engine and the input shaft of the automatic transmission; a retainer connecting a housing of the engine clutch to the torsion damper; a motor cover housing arranged to cover the right side surface of the motor rotor and the right side surface of the inner end of the motor support shaft and including a concave portion on the right side surface thereof; and a flywheel positioned at the concave portion of the motor cover housing to be blocked from the motor rotor.