In this study,the ultrasonic extraction process of raspberry pulp polysaccharides (RPP) was optimized using response surface methodology and the anti-fatigue activity of RPP was evaluated by swimming mice experiments.The results showed that the optimal ultrasonic extraction conditions of RPP were temperature 58 ℃,extraction time 84 min,ultrasonic power 58 W and material-liquid ratio 1∶20,in which the extract yield of RPP could reach 11.75%.RPP showed a typical polysaccharides infrared spectrum and was composed of galactose,rhamnose,glucose,xylose,mannose and arabinose,with the molar ratio of 2.3∶2.0∶7.1∶1.0∶1.1∶19.9. Furthermore,RPP exhibited significant anti-fatigue activity in the swimming mice experiments,for it could effectively improve the exercise endurance and adaptability of swimming mice,maintain the level of blood sugar and glycogen,reduce the production of lactic acid and accelerate its clearance.