An actuation device is provided herein to give self-acting toys more lively and appealing moves. The major characteristic of the present invention lies in that a motor is used to drive a gear assembly which in turn drives a gear on top of the gear assembly to rotate around the axle of the gear assembly. The gear therefore sequentially and periodically gets into contact with a number of eccentric gears arranged along the rotational path. These eccentric gears in turn drive their connecting rods which are connected to various parts of the self-acting toy to swing in various manners.