This paper discusses the minimal eigenvalue 1(p, q,) and its best estimate of the following nonlinear eigenvalue problem −pu = |u|q−2 u, u|@
= 0. Where is a bounded smooth domain in RN,p is the p-laplace operator, p 2, q 2 [p, Np N−p ). By this result, the famous Opial inequality in RN are deduced