A current sensing circuit is provided. The current sensing circuit includes an amplifier, an input resistor, a sensing resistor, and a feedback circuit. The amplifier has a first input terminal, a second input terminal, a third input terminal, and an output terminal. The input resistor is coupled between the first input terminal and the second input terminal of the amplifier. The sensing resistor is coupled between the second input terminal and the third input terminal of the amplifier. The feedback circuit is coupled between the first input terminal and the output terminal. When an input current flows through the sensing resistor, a voltage across the sensing resistor is equal to a voltage across the input resistor, and the feedback circuit correspondingly outputs a sensing voltage according to the input current.