Abstract: Kaempferol-3,7-O-α-L-dirhamnopyranoside was separated from Siraitia grosvenorii leaves using water extraction and macroporus resin adsorption methods.The free radical scavenging activity of kaempferol-3,7-O-α-L-dirhamnopyranoside was also determined.The results showed that kaempferol-3,7-O-α-L-dirhamnopyranoside could be easily obtained with >60% purity from Siraitia grosvenorii leaves.Furthermore,kaempferol-3,7-O-α-L-dirhamnopyranoside showed good free radical scavenging activity.The IC50 on DPPH was 9.08 mg/mL,and the IC50 on ABTS was 3.97 mg/mL.