A fastening and automatic ejecting structure for a battery of a notebook is provided, which comprises: a first fastening element disposed on a predetermined position of the computer and swinging to and fro between a first position and a second position in a predetermined direction; a second fastening element disposed on a predetermined position of the battery and moving to and fro between a third position and a fourth position in a predetermined direction along with the battery. Moreover, when the battery is pushed and moves from the third position to the fourth position, the first fastening element will be forced to swing towards the second position and to be bound with the predetermined position of the battery. When the battery is pushed again and moves from the fourth position to the third position, the first fastening element will be released from the battery.