The College of Science in the Department of Mathematics discussed a seminar entitled On Certain Curvature Tensors of C_5⊕ C_12-Manifolds  for postgraduate student Ali Adnan Abd AlA'li. This seminar focus on introduces the geometric properties and tensors components of a specific class of almost contact metric manifolds, namely the C_5⊕ C_12 class. We established the characteristic identity of this class on G-structure adjoined space and found the equivalent conditions for the defining condition of the class in terms of Kirichenko's tensors. We discussed the necessary and sufficient condition for C_5⊕ C_12-manifold to be almost C(λ)-manifold.