Nonylphenol ethoxylater, a nonionic surfactant was analyzed using Asahipak GF-310 HQ (an Aqueous/Organic (multi-solvent use) SEC column). The figure shows the chromatograms of different degree of POE polymerization. And, the table shows the elution time of the peaks. Moreover, the elution characterstics of of alkylphenol ethoxylate and alkyl ethoxylate using GS-310 HQ has important features as follows: 1) The surfactant of which molecular weight is larger elutes faster. 2) The reproducibility of the elution time of the peaks are very good and are independent of the typical degree of POE polymerization of the sample. These features are useful for the determination of the degree of POE polymerization.