The multiplicity of homoclinic solutions is obtained for a class of the p-Laplacian Hamiltonian systems d dt (|u(t)| p-2u (t))-a(t)|u(t)| p-2 u(t) + ∇W(t, u(t)) = 0 via variational methods, where a(t) is neither coercive nor bounded necessarily and W(t, u) is under new concave-convex conditions. Recent results in the literature are generalized even for p = 2.