A system (100) for monitoring a motor (202) includes a potential-detecting module (102), a potential-comparing module (104) and a motor-monitoring module (106). The potential-detecting module is configured for measuring output potential of the motor before operation of the motor, and measuring output potential during operation of the motor so as to determine a first output potential and a second output potential. The potential-comparing module is configured for comparing the first output potential with the second output potential to determine whether the motor is operating normally. The motor-monitoring module is configured for selecting a monitoring type if the motor is operating normally. A method for monitoring a motor is also provided.