The wall of rape bee pollens were broken by using different methods, and them the water-soluble ingredients were extracted. Therefore, the 4-Nitrophenyl α-D-glucopyranoside (PNPG) was as substrate to evaluate the efficiency of bee pollen as a natural alpha glucosidase inhibitor. The results showed that the wall-breaking manners had significant effect on the active ingredient. The inhibition rate of thealphaglucosidase was found ordered as following, temperature difference (13.73±1.15)%, supercritical CO₂ (-8.07±0.93)%, ultrasonic assisted enzymatic (16.70±0.87)%,and untreated (9.68±0.89)%. Moreover, the inhibition rate of rape pollen polysaccharide on alpha glucosidase activity was fluctuated at （2.46±0.31）%~（-0.78±0.03）%, and there was no obvious linear relationship. Finally, after the walls were broken, the content of polysaccharides increased significantly, but rape pollen polysaccharide had no effect on alpha glucosidase activity. This might be related to flavonoids or other components.