Pectin extracted from sugar beet was fractionated into four fractions by filtration. The structure and emulsifying properties of pectin from the fractios were characterized by HPLC, FT-IR and GC. The results showed that the content of pectin was the highest (64.86%) when the MWCO size membrane was above 100000. Molecular weight of beet pectin was related to its physicochemical properties. And the galacturonic acid content, the ferulic acid content and degree of esterification increased with the increase of the molecular weight. The pectin emulsifying properties depended on the molecular weight. The pectin with the molecular weight of 4.64×104 Da showed the highest emulsifying activity and stability.