In this paper we study the non-linear fractional Schrödinger equation with steep potential well (-Δ)αu + λV(x)u = f(x, u) in ℝn, u ∈ Hα(ℝn),where (-Δ)α (α ∈ (0, 1)) denotes the fractional Laplacian, λ is a parameter, V ∈ C(ℝn) and V-1(0) has nonempty interior. Under some suitable conditions, the existence of nontrivial solutions are obtained by using variational methods. Furthermore, the phenomenon of concentration of solutions is also explored.