Damage extension behavior at the notch tip in a short fiber reinforced SMC composite is experimentally examined from the view point of the release of elastic strain energy which is supposed to control the microcrack extension in brittle fiber-brittle matrix composites. We carried out experiments on the transparent nonfiller SMC composite which enabled us to see clearly the microcracks in the damage region, and we realized that almost all the microcracks were debondings of strands. Damage initiates at the early stage of loading and afterwards extends rapidly with the sudden increment of AE signals, which corresponds to the beginning of fiber breakage at the notch tip. However, the amount of released elastic strain energy appears to be roughly proportional to the accumulated AE energy and also to the area of damage region, and these linear relationships are not affected by the beginning of the fiber breakage. These facts lead us to the conclusion that the release of elastic strain energy during the whole fracture process of the SMC composite is owing mostly to the debondings of strands.