Along with traditional world economic fisheries resource decline, the exploitation and utilization of Cephalopod resource have been recognized generally in the world and studies on resource condition and biology were made much progress. Beak with the features of steady structure, erode-resistant and better information storing is one of hard and main predation organs of Cephalopod, and it not only play an important role in taxonomy also as a good tool to study Cephalopod biology. Based on the studies conducted by some authors at home and abroad, our paper describe the morphological characteristics of beak and review the studies of beaks that applied in Cephalopod biology, taxonomy, stock estimation and feeding habits of predators. The results shows that some problems still exist in age identifying and stock estimating, which should be solved in the recent future although a certain progress has been made.