Abstract: An electric toothbrush is provided a cam mechanism and a crank mechanism in the handle. The cam mechanism comprises a cam, mounted on a rotary shaft of a motor via a frame; and a slave unit making a reciprocating movement, defined within the handle and engaged with the cam. The crank mechanism comprises a crank, mounted concentrically with the brush head; a link rod, jointed with the crank; and a block, defined within the brush body and engaged with the slave unit. Therefore, the structure of the electric toothbrush of the present invention is simplified, thus its cost can be reduced accordingly. In addition, the brush head of the present invention can be formed star shape or be inclined to improve the area of contact for super cleaning and be convenient for removing the deposit on the teeth.