Disclosed is a torque converter in a vehicle, which permits putting a lock-up clutch into operation while sufficiently attenuating vibration at all rotation speed ranges of a low rotation speed range to a high rotation speed range of an engine.The torque converter in a vehicle includes a lock-up clutch and a torsional damper, wherein the torsional damper has one side with a first centrifugal absorbing unit provided thereto for absorbing vibration and impact by centrifugal force, and a spline hub has one side with a second centrifugal absorbing unit for absorbing vibration and impact by centrifugal force.