Electronic Journal of Differential Equations, Vol. 2014 (2014), No. 77, pp. 1-13. Title: Sign-changing solutions of a fourth-order elliptic equation with supercritical exponent Author: Kamal Ould Bouh (Taibah University, Saudi Arabia) Abstract: In this article we study the nonlinear elliptic problem involving nearly critical exponent $$\displaylines{ \Delta^2 u = |u|^{8/(n-4)+\varepsilon}u\quad\text{in } \Omega, \cr \Delta u=u = 0\quad \text{on } \partial \Omega, }$$ where $\Omega $ is a smooth bounded domain in $\mathbb{R}^n $ with $n \geq 5 $, and $\varepsilon$ is a positive parameter. We show that, for $\varepsilon$ small, there is no sign-changing solution with low energy which blow up at exactly two points. Moreover, we prove that this problem has no bubble-tower sign-changing solutions. Submitted November 15, 2013. Published March 19, 2014. Math Subject Classifications: 35J20, 35J60. Key Words: Sign-changing solutions; critical exponent; bubble-tower solution.