In this study, we define some new types of non-null ruled surfaces called slant ruled surfaces in the Minkowski 3-space 3 1 E . We introduce some characterizations for a non-null ruled surface to be a slant ruled surface in 3 1 E . Moreover, we obtain some corollaries which give the relationships between a non-null slant ruled surface and its striction line in 3 1 E . MSC: 53A25, 53C50, 14J26.