Danggui Buxue Decoction has shown the effects of significantly promoting the splenic capacity of healthy mice in generating clone-stimulating factors (CSFs) both in spleen conditioned medium (SCM) and in lung conditioned medium (LCM), and markedly enhancing the capacity of the lungs of blood-deficient mice in generating CSFs in spleen conditioned medium. CSFs generation in SCM is promoted in the spleen of healthy mice given Angelica sinensis, but markedly inhibited if Astragulus menbranacous is used. The results suggest that blood-tonifying and blood-activating effects of Danggui Buxue Decoction are associated with its CSFs secretion-stimulating action, which is brought about by Angelica sinensis.