Abstract: A control device for an electric fan comprising a power supply, a control means, a trigger pulse generator and a switch means, all connected in circuit with the motor of the electric fan, wherein the trigger pulse output of said trigger pulse generator is connected to trigger said switch means and is controlled through said control means to thereby achieve a stepless, variable speed control for the electric fan. Other forms of the device may further comprise a delay means, and/or delay reverse means, and/or wave generator means and/or any combination thereof, connected in the above circuit to accomplish stepless speed reduction and/or delay speed-down reverse and/or various kinds of imitative natural wind rotational speeds for the electric fan.