Electronic Journal of Differential Equations, Vol. 2007(2007), No. 112, pp. 1-7. Title: Multiple positive solutions for nonlinear third-order three-point boundary-value problems Authors: Li-Jun Guo (Lanzhou Univ. of Technology, China) Jian-Ping Sun (Lanzhou Univ. of Technology, China) Ya-Hong Zhao (Lanzhou Univ. of Technology, China) Abstract: This paper concerns the nonlinear third-order three-point boundary-value problem $$\displaylines{ u'''(t)+h(t)f(u(t))=0, \quad t\in (0,1), \cr u(0)=u'(0)=0, \quad u'(1)=\alpha u'(\eta ), }$$ where $0<\eta <1$ and $1<\alpha <\frac 1\eta $. First, we establish the existence of at least three positive solutions by using the well-known Leggett-Williams fixed point theorem. And then, we prove the existence of at least $2m-1$ positive solutions for arbitrary positive integer $m$. Submitted April 18, 2007. Published August 18, 2007. Math Subject Classifications: 34B10, 34B18. Key Words: Third-order boundary value problem; positive solution; three-point boundary value problem; existence; cone; fixed point.