Objective:To evaluate the effect of ligustrazine on bone marrow hematopoietic microenvi-ronment and signal transduction in irradiation injured mice. Methods:After being irradiated by 6.0 Gy 60Coγ-ray, the mice in the ligustrazine group were orally given ligustrazine 4 mg/mouse twice a day to the endof the experiment. For the control group, normal saline was given instead of ligustrazine and the mice inthe normal group was untreated. The mice were sacrificed separately on the 3rd, 7th and 14th day after ra-diation, bone marrow of them was taken and managed as follows: (1) Make stromal cell culture to observethe growth state and the expression of focal adhesion kinase (FAK) of the cells; (2) Make the bone mar-row section to examine the pathological and immunohistochemistry changes, including the expression of fe-tal liver kinase-1 (Flk-1) and Fvm: RAg. The data were recorded and compared among groups. Results:Af-ter radiation, the hematopoietic cells in bone marrow decreased and the micro-vessels dilated and congestedwith bleeding; bone marrow became thinner, red colored with cells of irregular shape and few cells adhereto the bottom of culture flask. These changes began to recover at the 7th day and approached to normalwithin 2 weeks. The recovery was better, earlier and quicker in the ligustrazine group than that in the con-trol group. The expression levels of Flk-1 decreased significantly. Conclusion: Ligustrazine could promotethe recovery of hematopoietic function of radiation damaged bone marrow, the mechanisms might bethrough improving the microenvironment and signal transduction path for recovery.