Title: The integral cohomology ring of E_8/T^1 E_7 Author: Masaki Nakagawa AMS classification numbers: Primary:57T15; Secondary:55T10 Address of author: Department of General Education, Takamatsu National College of Technology, 355 Chokushi-cho, Takamatsu, 761-8058, Japan E-mail address of author: nakagawa@takamatsu-nct.ac.jp Abstract: The generalized flag manifolds are homogeneous spaces of the form G/C, where G is a compact connected Lie group and C is the centralizer of a torus in G. These homogeneous spaces play an important role in algebraic topology, algebraic geometry and differential geometry. In this paper, using the Borel presentation and a method due to Toda, we determine the integral cohomology ring of a certain generalized flag manifold which is a quotient space of the exceptional Lie group E8.