The mechanism of immunomodulation of maternal-fetal interface after pregnancy is very complex, it cannot be simply considered as immunosuppression between mother and fetus.Immunotherapy in pregnancy should focus on immune regulation.Based on the theory of zang-fu organs, Qi & blood of TCM and combined with the principles of modern reproductive immunology, professor Jin Zhichun believes that kidney and spleen organs are the basis of reproductive immunity and Qi & blood are the key to reproductive immunity.He also emphasizes the key role of tonifying kidney and spleen, harmonizing Qi and blood in fetal protection.It is clinically used for the prevention and treatment of recurrent spontaneous abortion and has achieved highly curative effect.