Abstract: A yo-yo include a soft body made of foam material and formed with a cavity having a passage extending through the body, and a vibrator fitted inside the cavity of soft body and including a housing, a transmission device fitted inside the housing, an eccentric disk mounted on the transmission device, and a reel mounted on the transmission device, the transmission device including a casing composed of two symmetric shells, a spiral spring arranged inside the casing and drivingly connected with the reel, a ratchet member engaged with the spiral spring, a gear train engaged with the ratchet and drivingly connected with the eccentric disk, the reel being provided with a string extending through the passage of the soft body, whereby the yo-yo can automatically vibrate and go up a string hence facilitating its operation and making it attractive and interesting.