Objective To establish the technics of preparing the particle product of Chaenomeles chinensis superoxide dismutase extract (PC-SOD) and investigate the biological function of PC-SOD.  Methods Enzymatic technique was applied to improve extraction rate. The activity of SOD during the process of preparing PC-SOD was explored by adopting γ-dextrin and β-dextrin for packing. The biological function of PC-SOD was studied by detecting MDA contents and SOD activity in blood serum

liver and kidney of mice treated with PC-SOD product.  Results In enzymatic process

juice recovery was higher and the total SOD activity was 10.65% higher than non-enzymatic procedure. Using 3% γ-dextrin to pack SOD and prepare PC-SOD

the activity rate of SOD in PC-SOD was 67.8%. In mice fed with PC-SOD product

the MDA content in blood serum

liver and kidney was lower

while the SOD activity was higher than the control animals.  Conclusion This technique of preparing the particle product of Chaenomeles chinensis PC-SOD is effective. PC-SOD reduces MDA content in blood serum and organs of mice

and increases the SOD activity.