Objective To disclose the relationship between aquaporin-4（AQP-4）and apparent diffuse coefficient （ADC） by analyzing the magnetic resonance diffusion weighted imaging（MRI-DWI） of acute cerebral ischemia and reperfusion in rabbits. Methods Fifty- eight New Zealand white rabbits were divided into permanent ischemia group(A group, EM>n/EM>=30)which were subdivided into 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, 48 hours groups, and reperfusion group after 1 hour cerebral ischemia (B group, n=28)which were subdivided into 0 hour, 2 hours, 5 hours, 11 hours, 23 hours, 47 hours groups. All rabbit brains were cut out to make histologic section immediately after each time point MRI examination. AQP-4 detection was carried out in bilateral cortical and corpus striatum region respectively under microscope. ADC and rADC value and positive cells of AQP-4 were calculated and recorded. Results The hyperintensity area in MRI-DWI tended to enlarge gradually in permanent ischemia groups. The relative apparent diffusion coefficient （rADC） value decreased at first and then increased gradually. In reperfusion groups, the rADC value increased at the 2nd hour point with shrinkage of hyperintensity area on DWI.After 5 hours of reperfusion, the rADC value increased again with enlargement of DWI hyperintensity area. AQP-4 positive cells decreased within 6 hours, and then went up in permanent ischemia groups. There was a close relationship between rADC value and AQP-4 positive cells(EM>r/EM>=0.943, EM>P/EM>=0.005). The same things happened in reperfusion groups within 5 hours, but the scope of chan