A radio frequency (RF) switch system, an RF switch protective circuit, and a protecting method thereof are provided. The RF switch system may include an RF switch and a protective circuit. The RF switch may be connected between a port that receives an RF signal and a ground. The protective circuit may detect a first voltage that is a voltage that is generated when the first RF switch is turned off, and may transmit an impedance value that is varied based on the first voltage to the port.