Abstract: Objective: To guarantee ovotransferrin( OVT) quality as a food allergen reference material candidate,ovotransferrin was prepared with high purity,and the physicochemical and immunological properties were characterized well. Methods:Ovotransferrin was prepared through two step chromatographies,followed by being subdivided and lyophilized. Afterwards,the prepared ovotransferrin was identified by MALDI TOF / TOF,and the purity was tested by SDS- PAGE with silver staining,followed by measuring the structure by circular dichroism spectroscopy,fluorescence spectroscopy and1 H NMR.The content and stability were detected by Bradford protein assay and SDS- PAGE with silver staining. The potential allergenicity of ovotransferrin was assessed by ELISA. Results: The prepared protein was identified to be egg ovotransferrin by MALDI TOF /TOF,with a molecular weight of 79.55 ku and a p I of 6.85.The purity of ovotransferrin was 94.6%.The prepared ovotransferrin maintained its natural structure,and the lyophilization had no significantly effect on ovotransferrin structure. The stability,quality and Ig E- binding capacity showed no significant difference within 5 months storage period at 4 ℃. Conclusion: The prepared egg allergen ovotransferrin could be qualified as a reference material candidate.