A method and apparatus for detecting a position of a mobile robot are disclosed to accurately and precisely detect a position of a mobile robot on the basis of a time difference between an infrared signal and a ultrasonic signal. The infrared signal and the ultrasonic signals are received, a time difference between the received infrared signal and the ultrasonic signals, and then, a position of a mobile robot is detected on the basis of the calculated time difference value and a distance value previously stored between ultrasonic wave generators generating the ultrasonic signals.