Abstract
1. $\ll$Graphical Materia Medica$\gg$ is first book that writes about Rehmanniae Radix Preparat. $\ll$Shen nong's herbal$\gg$ is only written about Rehmanniae Radix. 2. After the $\ll$Decoction Materia Medica$\gg$, orintal dortors use Rehmanniae Radix's effect is removing heat from the blood and Rehmanniae Radix's effect is enriching the blood. 3. Rehmanniae Radix Preparat is kinds of durgs for enriching the blood, because Rehmanniae Radix Preparat's effect do nourishing yin and supplementing blood. Therefore, Rehmanniae Radix Preparat is uesd simple recipe or Rehmanniae Radix Preparat is used with another herbs that shows so good effect of hematogenous functions at laboratory work. 4. Bone marrow is doing hematogenesis. That has relation to Rehmanniae Radix Preparat's effect is replenishing bone marrow, it's channel tropisms are liver kidney channels. 5. Rehmanniae Radix Preparat's guide component is 5-HMF, but effective component has relation with hematogenesis is mannitol of saccharides. And we need more reserch about Rehmanniae Radix Preparat.