Abstract
We study warped product semi-invariant submanifolds of nearly cosymplectic manifolds. We prove that the warped product of the type M-perpendicular to x M-f(T) is a usual Riemannian product of M-perpendicular to and M-T, where M-perpendicular to and M-T are anti-invariant and invariant submanifolds of a nearly cosymplectic manifold (M) over bar, respectively. Thus we consider the warped product of the type M-T x M-f(perpendicular to) and obtain a characterization for such type of warped product.