For the first time, comprehensive two-dimensional liquid chromatography (2D-LC) of complex polymers is coupled online to H-1 NMR 2D-LC is used to separate mixtures of poly(ethylene oxide)s with regard to chemical composition and molar mass. The present samples contain polymers with different end groups and chain distributions. In the first LC dimension, liquid chromatography at critical conditions (LCCC) is used for the selective separation according to the end groups. Fractions that are then uniform regarding their end groups are automatically transferred into the second LC dimension which separates the fractions regarding their chain length distributions using liquid adsorption chromatography. The eluate from 2D-LC is directly introduced into the H-1 NMR for on-flow analysis. The online coupling of one- and two-dimensional chromatography with H-1 NMR detection is demonstrated. The NMR is coupled to both individual separations as well as to the entire two-dimensional separation. As a result of this multidimensional analysis quantitative information is obtained on the types and topology of end groups and the chain length distributions within each functionality fraction.