S.cumini fruit at eighty percent ripe stage was used as material for this research.The extraction of proanthocyanidins from the fruits was studied by butanol-hydrochloric acid technology.The yield was by measuring the absorbance of the product.According to single factors tests and orthogonal optimization,the results showed that the optimal conditions were: concentration of acetone were 60%(pH=3),the ratio of extraction solution to sample was 9,the extraction temperature was 60℃ and the extraction time was 2h.The proanthocyanidins yield was 91.52% after being extracted 2 times.The proanthocyanidins content in the S.cumini fruit at eight percent ripe stage was 5.96%,which was 133.04% times of fully ripen fruits.