Abstract: An over-current alerting circuit used in a hand held device includes a current sensor module, a photo sensor module and an alerting module. The current sensor module is used for sensing a loading current of the hand held device and outputting a photo signal according to the intensity of the loading current. The photo sensor module is used for generating a driving signal when the intensity of the photo signal is higher than a predetermined intensity. The alerting module is used for performing an alerting action after the driving signal is received. In addition, an over-current alerting method is also disclosed herein.