The optimal extraction parameters of Mopan persimmon polysaccharide (MPP) were ultrasonic power 900 W, ultrasonic treatment time 3 min, and water addition 2000%. Four subfractions (MPP-1, MPP-2b, MPP-3, and MPP-4b) were separated by DEAE52 cellulose anion-exchange column chromatography and then Sephadex G-200 gel column chromatography. The in vitro scavenging effects of MPP and MPP-4b at a dosage of 10 g/L on hydroxyl radical were 94.15 +/- 8.27% and 96.61 +/- 8.06%, respectively. The 1,1-diphenyl-2-picrylhydrazyl inhibition percentages of two polysaccharides fractions were 93.37 +/- 7.66% and 70.79 +/- 6.15%, respectively. The reducing power (absorbance at 700 nm) of MPP and MPP-4b were 4.31 +/- 0.26 and 5.09 +/- 0.33, respectively. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012