Electronic Journal of Differential Equations, Vol. 2012 (2012), No. 111, pp. 1-16. Title: Multiplicity of positive solutions for quasilinear elliptic p-Laplacian systems Authors: Asadollah Aghajani (Iran Univ. of Science and Tech., Tehran, Iran) Jamileh Shamshiri (Islamic Azad Univ., Karaj, Iran) Abstract: We study the existence and multiplicity of solutions to the elliptic system $$\displaylines{ -\hbox{div}(|\nabla u|^{p-2} \nabla u)+m_1(x)|u|^{p-2}u =\lambda g(x,u) \quad x\in \Omega,\cr -\hbox{div}(|\nabla v|^{p-2} \nabla v)+m_2(x)|v|^{p-2}v=\mu h(x,v) \quad x\in \Omega,\cr |\nabla u|^{p-2}\frac{\partial u}{\partial n}=f_u(x,u,v),\quad |\nabla v|^{p-2}\frac{\partial v}{\partial n}=f_v(x,u,v), }$$ where $\Omega\subset \mathbb{{R}}^N$ is a bounded and smooth domain. Using fibering maps and extracting Palais-Smale sequences in the Nehari manifold, we prove the existence of at least two distinct nontrivial nonnegative solutions. Submitted June 19, 2012. Published July 02, 2012. Math Subject Classifications: 35B38, 34B15, 35J92. Key Words: Critical points; nonlinear boundary value problems; quasilinear p-Laplacian problem; fibering map; Nehari manifold.