| In this paper, we study the following Neumann boundary problem with Sobolev critical exponent where α,β> 1,α+β=2*:=2N/(N-2)(N≥3) and Ω, is a bounded domain in RN(N≥3) with αΩ∈C2, n denote the unit outward normal vector at boundary αΩ.. We prove the existence of positive solutions of the above elliptic system for some ranges of the parameters α,β, N and λ. |