A voltage tracking circuit is provided and includes first and second P-type transistors and a voltage reducing circuit. The drain of the first P-type transistor is coupled to a first voltage terminal. The voltage reducing circuit is coupled between the first voltage terminal and the gate of the first P-type transistor. The voltage reducing circuit reduces a first voltage at the first voltage terminal by a modulation voltage to generate a control voltage and provides the control voltage to the gate of the first P-type transistor. The gate of the second P-type transistor is coupled to the first voltage terminal, and the drain thereof is coupled to a second voltage terminal. The source of the first P-type transistor and the source of the second P-type transistor are coupled to the output terminal of the voltage tracking circuit. The output voltage is generated at the output terminal.