Abstract: Aim at obtaining iron-containing protein from earthworm as nutrient, aqueous two-phase extraction and other methods were performed in purification process based on the characters and their exist state of hemoglobin in earthworm body. Results showed that using directly isoelectric point precipitation at pH 5.1 after the aqueous two-phase extraction composed of 12%(W/W)polyethylene glycol and 12%(W/W)ammonium sulfate may separate well the iron-containing protein from other substances. Addition of the ion exchange chromatography Q Sepharose fast flow column in final process may get pure Lumbyicus terrestris hemoglobin. The preparation of iron-containing protein product in high quality from earthworm was simple, per- formed easily with lower cost based on this study, which was very useful for manufacture blood tonic food utilizing earthworm asm aterials.

Key words: earthworm, iron-containing protein, purification, aqueous two-phase extraction