Polypeptide of ascidicea and preparation thereof

Ascidian polypeptide and its production are disclosed. The procedure is carried out by immersion depressing at normal temperature by alcohol, recovering alcohol to obtain extract, extracting by organic solvent, concentrating, separation purifying by macroporous resin chromatography, silica-gel chromatography and Sephadex LH20 chromatography, gradient eluting by eluent in proportion of CHCl3: MeOH: H2O=7:3:0.5, and collecting concentrated eluent with thin-layer chromatographic ultraviolet verification Rf=0.5í½0.6. The molecular weight of ascidian polypeptide is 711.4. It is simple, has less investment, convenient control for production and various raw materials.