Abstract: Proanthocyanidins, a class of bioflavanoids found in many plants, can work as an effective antioxidant and eliminate free radicial etc., which have made it to be developed into nutritional or therapeutic supplements in the World. Among the fruit crops, grape seed is the most common and richest source of proanthocyanidins, and has gain attention of medical researchers and nutritionists. The collection of the information about the metabolism of proanthocyanidins in grape and some related scientific research discoveries can be great help to us for the regulation of the metabolic pathway, more efficient utilization of proanthocyanidins, and the improvement of grape quality, based on which we briefly introduce the molecular structures, the classification, and the metabolic pathway of proanthocyanidins. The research advances of the important enzymes involved in the metabolic pathway are also emphasized.