The purpose of the research was to develop functional products derived from immature persimmon and improved its application value. Using the immature persimmon as test material， a comprehensive method combined by water extraction， gelatin precipitation process and organic solvent extraction was used to extract and separate the persimmon extracts， then three separated components F1， F2 and F3 were obtained. The components of tannin were identified by ultraviolet spectrum， infrared spectrum and HPLC analysis， as well as their antioxidative activity， antibacterial activity and anticancer activity in vitro were also evaluated. The results revealed that the separated components F1， F2 and F3 had similar absorption characteristics with tannins， and the molecular structures were highly similar， all containing -OH， aromatic ring skeleton， C=C， C-H structure. F1 contained 240.9 mg/g gallic acid and four unknown ingredients， F2 contained 270 mg/g protocatechin and two unknown ingredients， and F3 contained 37.8 mg/g ferulic acid and four unknown ingredients. DPPH radical scavenging ability was F1>F3>VC>F2， ABTS radical scavenging ability was F1>VC>F3>F2， hydroxyl radical scavenging ability was VC>F1>F3>F2， and total reducing capacity was VC>F3>F2>F1， indicating that F1， F2 and F3 all had strong antioxidative properties. Three components had different degrees of inhibition on Staphylococcus aureus， E. coli， Shigella， Salmonella， and Sakazakii， meanwhile， the antibacterial ability was F1>sodium benzoate>F3>F2. Both F2 and F3 had no inhibitory properties on tumor cell proliferation， and only F1 had a certain inhibitory effect on the proliferation of human liver cancer cells HepG2 and human gastric cancer cells MKN-45 in vitro. Conclusion： Immature persimmon tannin had the potential to be developed into natural antioxidants， preservatives and anti-cancer drugs.