In this paper, we establish some upper bounds for numerical radius inequalities including of 2 × 2 operator matrices and their off-diagonal parts. Amongwhere X, Y are bounded linear operators on a Hilbert space H , r ≥ 1 and f , g are nonnegative continuous functions on [0, ∞) satisfying the relation f (t)g(t) = t (t ∈ [0, ∞)). Moreover, we present some inequalities involving the generalized Euclidean operator radius of operators T 1 , · · · , T n .