A motor protection device includes a detection unit for detecting an operating state of a motor and outputting a detection signal; a reference unit for generating a variable reference signal; a discriminating unit for comparing the detection signal with the variable reference signal to discriminate whether the motor is in an abnormal condition; and a protection unit that receives a result of discrimination from the discriminating unit and limits a driving current for the motor when the motor is in an abnormal condition. The motor protection device is characterized in that the reference unit adjusts the variable reference signal according to a motor rotation detection signal, so that the motor rotation detection signal and the detection signal are used synchronously in discriminating whether the motor is in an abnormal condition, and the motor in an abnormal condition may be doubly protected.