Gui zhi, the chief herb, unblocks the blood vessels and reduces the stasis of blood by promoting circulation. The deputy herbs are tao ren, mu dan pi, and shao yao. These three herbs invigorate the blood, break up and dispel blood stasis, reduce fixed abdominal masses, and disperse accumulation. Mu dan pi disperses heat due to the blood stasis. Because phlegm-dampness may contribute to the formation of masses or the blockage and stasis of blood, fu ling is used to tonify the spleen and thus the transporting and transforming of phlegm-dampness. So the focus of this formula is to treat blood stasis in lower burner, especially blood stasis during pregnancy.