In this paper,the factors,such as fragments initial velocity,the mass and shape of a single fragment,the blasting height,impact angle and terminal velocity of the projectile and so on,which affect the lethality of premade fragments were analyzed,and the conditions,which make the lethal area largest,were calculated,and the theoretic gist for optimum design of the projectile were provided.

To meet the requirements of penetrating,which induces a larger impact angle and a smaller terminal angle of attack,the terminal attitude control should be added to laser-guided bombs guidance.

I call those stories which happen in the corners as“the corner stories.

Enlightenment gained from the violent ups and downs of Japanese economy;