Extracting effects of six chemical additives with water were studied in terms of content and purity of tannin using Chinese chestnut shell as raw material. Result indicated that as an impregnant the extracting effect of alcohol liquid is the best judging from the improvement of content and purity of tannin. The technological conditions for extracting vegetable tannin extract from Chinese chestnut shell were selected by orthogonal test, including extracting temperature (A), extracting time (B) and alcohol do...