Objective To evaluate the effect of ultra-filtration extract from Danggui Buxue Decoction (DBD) on immune function of H22 bearing mouse and explore the mechanism through observing the effect of ultra-filtration extract from DBD on the secretion of the cytokines (IL-2,IFN-?).Methods We used membrane separation technique to extract DBD.The content of IL-2 and IFN-? in splenocyte culture supernatant was detected by enzyme-linked immunosorbent assay (ELISA),and the mRNA expression of cytokines (IL-2,IFN-?) in splenocytes was assayed by reverse transcription-polymerase chain reaction ( RT-PCR).Results The content of IL-2 and IFN-? in splenocyte culture supernatant was increased in ultra-filtration extract from DBD groups,significantly in high-dose group (P