A novel analytical method called two-dimensional correlation gel permeation chromatography (2D GPC) is introduced. In 2D GPC, generalized two-dimensional (2D) correlation analysis is combined with time-resolved gel permeation chromatography (GPC). This technique can be used effectively, for example, to study intricate details of a polymerization process. In this study, a sol-gel polymerization process of octyltriethoxysilane catalyzed by 1.0 M HCl .H2O is traced as a function of reaction time using the GPC technique. A set of GPC traces sequentially collected at different sampling points during the polymerization reaction are then converted to two-dimensional correlation maps. It has been found that the 2D GPC maps created by the correlation analysis directly reflect the reaction mechanism in the polymerization process, thus demonstrating the promising potential of this technique.