In this work, we define Rad− ⊕ −supplemented and strongly Rad− ⊕ −supplemented lattices and give some properties of these lattices. We generalize some properties of Rad− ⊕ −supplemented modules to lattices. Let L be a lattice and 1 = a 1 ⊕a 2 ⊕. . .⊕a n with a 1 , a 2 , . . . , a n ∈ L. If a i /0 is Rad− ⊕ − supplemented for every i = 1, 2, . . . , n, then L is also Rad− ⊕ − supplemented. Let L be a distributive Rad−⊕−supplemented lattice. Then 1/u is Rad−⊕−supplemented for every u ∈ L. We also define completely Rad− ⊕ −supplemented lattices and prove that every Rad− ⊕ −supplemented lattice with SSP property is completely Rad− ⊕ − supplemented.