Abstract The analysis of uronic acids such as d-galacturonic acid, d-glucuronic acid, d- mannuronic acid and l-guluronic acid and the analysis of oligogalacturonic acids by high-performance liquid chromatography was studied. The uronic acids were separated on a strong anion-exchange column with acetic acid as eluent. d-Galacturonic acid and l-guluronic acid could not be separated. A mixture of unsaturated oligogalacturonic acids obtained by enzymatic degradation of pectic acid (pectic acid lyase) was successfully separated by three different systems based on ion exchange or ion-pair chromatography. The influence of the eluent composition on the performance of these systems was investigated. Also normal oligogalacturonic acids coudl be separated. The methods were applied to the characterization of alginate samples with respect to their uronic acid composition and to the analysis of digests of enzyme- degraded pectins. The methods also proved to be very helpful in the elucidation of the fine structure of pectin.