Abstract. Let B(H) be the space of C * -algebra of all bounded linear operators on a complex Hilbert space H.The norm of the sum of bounded linear operators on H has been attracted the attentions of many mathematicians for along time. In this work, we study the upper bound of the sum of operators belong in B(H) under the usual operator norm given by A = sup x =1 < Ax, Ax >; x ∈ H. Moreover, we establish and generalize inequalities for the operator norm of sums of bounded linear operators in Hilbert spaces.