In order to investigate the effect of irradiation with ,12,C,6+, ions on the space memory of the Kunming mouse, the mouse brain was irradiated with ,12,C,6+, ions at low doses of 0, 0.5, 1 and 2.0Gy respectively. It was shown that the speed of looking for baits decreased with irradiation doses and then increased with the increment of the training times while the 8-arms radial maze was tested for determination of space memory. And the speed of looking for baits in irradiated and then trained groups recovered to the control level at 17,th, day after irradiation. It was also found that the space memory of the mice decreased along with the irradiation dose, but recovered to the control level at 20th day after irradiation. The data suggested that the irradiation of 0~2Gy ,12,C,6+, ions affected the mouse space memory in a short period of time, and then it could be recovered with time gradually after the irradiation by training.