Aim To study the change of interleukin-10 (IL-10) in focal ischemia tissue of brain and serum in middle cerebral artery occlusion (MCAO) of rats. Methods The middle cerebral artery (MCA) was occluded for different time with modified Zea Longa' s MCAO model. The level of interleukin-10 in focal ischemia tissue of brain and blood serum was measured with double-antibody sandwich enzyme linked immunosorbent assay (ELISA), both in ischemia group and in control group. Results The content of interleukin-10 in focal ischemia tissue of brain was lower at 3 h after ischemia, compared with the control (P> 0.05), and it fell to the lowest degree at 6 h, compared with the control (P< 0.01), then it increased compared with the control (P< 0.05). The concentration of interleukin-10 in serum fell to the lowest degree at 3 h after ischemia compared with the control (p<0.05), and then it increased slowly compared with the control (p< 0.05). Conclusion Interleukin-10 perhaps afford protection to the cerebral ischemia injury.