Abstract: To optimize the extraction process of Maca polysaccharide and improve the yield of maca polysaccharide. The response surface methodology was used to investigate the effects of ultrasonic temperature （A）, extraction time （B） and solid-liquid ratio （C） on the extraction rate of maca polysaccharide, and the interaction among them （A×B, A×C, and B×C） was investigated, and the optimal extraction conditions were obtained. Results showed that the optimum conditions were as follows： Ultrasonic temperature 60 ℃, extraction time 40 min, liquid-solid ratio 40∶1. Under the optimum conditions, the extraction rate was 51.21%.

Key words: Maca, ultrasound extraction, polysaccharide, response surface