The effects of the traditional Chinese drug Jianpi Bushen Prescription (JBP) were investigated on expressions of Wnt3a and Cyclin D1 genes in radiation-damaged mice. The radiation damage model was induced in Kumming mice by single total body irradiation treatment for 9 days. Mice were divided into the radiation group, low-dose (100%) JBP group, high-dose (200%) JBP group, or batyl alcohol group (positive control), which were administered twice a day for 9 days. mRNA and protein expressions of Wnt3a were detected in bone marrow mononuclear cells by real-time polymerase chain reaction and Western blot, whereas Cyclin D1 mRNA was detected by in situ hybridization. Wnt3a expressions were significantly downregulated in the radiation damage model group compared with all other groups (P < 0.05).