Acid （citric acid）， alkaline （sodium hydroxide） and enzymatic （endo-galacturonase） methods were applied in present study to extract pectic polysaccharide from potato pulp. The effects of the three extract methods on the yield， monosaccharide composition， esterification degree， molar mass and chain morphology of potato pulp pectic polysaccharides were evaluated. Results indicated that three potato pulp pectic polysaccharides were all rich in rhamnogalacturonan-I （RG-I） structure with large amount of galactan side chain. The highest yield was obtained by alkaline extracted pectic polysaccharide （23.1%）， followed by the acid extracted （11.7%） and the enzymatic extracted （6.0%）. All the three had very low degree of methylation （DM） （0 to 7.5%）， while the degree of acetylation （DA） were all relatively higher than traditional citrus pectin. DA for potato pulp pectic polysaccharides extracted by acid and enzymatic methods were higher （respectively as 13.6% and 10.7%） than that in the alkaline extracted （6.6%）. The highest molecular weight was observed in pectic polysaccharide extracted by enzymatic method （1 706.3 ku） with the narrowest distribution. Mark-Howink-Sakurada equation obtained by laser scattering method determined that potato pulp pectic polysaccharide extracted by enzyme had a high degree of branching， and the chain morphology was the most concentrated and closest to the spherical conformation. The morphology of pectic polysaccharide extracted by acid was between sphere and coil， while the morphology of the alkaline extracted was relatively loose and showed as a conformation of random coil.