A circuit for synchronous rectifying is provided for forward power converter. A secondary winding of a transformer includes a first terminal and a second terminal for generating a switching voltage. A saturable inductor is coupled from the second terminal to a third terminal for providing a delay time. A first transistor is coupled from the first terminal to a ground terminal. A second transistor is connected from the third terminal to the ground terminal. The first and second transistors operate as synchronous rectifiers. An inductor is equipped from the third terminal to an output terminal of the forward power converter. Furthermore, a current-sensing device generates a current signal in response to an inductor current of the inductor. A control circuit receives the switching voltage and the current signal for generating a plurality of signals for driving a plurality of transistors, respectively.