Grape seed contains many polyphenolic compounds that have potential health-promoting benefits. Among the-se compounds are proanthocyanidins, also known as condensed tannins, which is a class of flavanols. The basic structural building blocks of flavanols are polyhydroxyflavan-3-ol units linked together by C-C bonds. They are widely distributed in plants but grape seed has very high contents. This study examined extraction and purification technologies for obtain-ing proanthocyanidins from grape seeds and analytical methods and tools for characterizing them.