Abstract: OBJECTIVE To investigate the protective role of aqueous extract from Fici Hirtae Radix for bone marrow cells DNA of ⁶⁰Coγ-ray irradiated mice. METHODS Forty SPF male mice were randomized into 5 groups. Negative control group was given normal saline, irradiated group was radiation model group and 3 Fici Hirtae Radix dose groups were orally given aqueous extracts from Fici Hirtae Radix of 5, 10, 20 g·kg^-1·d^-1 for 7 consecutive days. Except the negative control group, all mice received 6 Gy irradiation of whole body. After 24 h of irradiation, mice were sacrificed on femur. Single cell suspension was produced. DNA damage was detected using single cell gel electrophoresis experiment. RESULTS The results showed that Tail DNA% and Tail Moment of radiation model mice were higher than negative control group (P<0.01). Tail DNA% and Tail Moment of all Fici Hirtae Radix dose groups were significantly lower than radiation model group(P<0.01). As the dose increased, Tail DNA% and Tail Moment reduced. CONCLUSION Aqueous extracts from Fici Hirtae Radix have good protective effect on ⁶⁰Coγ-organization of bone marrow cells DNA damage in mice.