Major objective of this lecture is to present on Trench Warfare in World War I. Trench Warfare a type of combat in which opposing troops fight from trenches facing each other. This lecture briefly describe on the Trench System: Front line; Communication trench; Support trenches; No Mans Land and Barbed wire. Trench Warfare means: Offensive attacks into No Mans Land; Shell fire; Going over the top; Retreat and the enemy goes forth.