Objective To investigate the application value of intravoxel incoherent motion diffusion weighted imaging(IVIM-DWI) in evaluating the microcirculation and water molecule diffusion of brain white matter of leukoaraiosis patients. Methods 20 cases of leukoaraiosis(LA) patients confirmed with conventional MR imaging, normal control group 10 cases. Compare LA white matter lesions, LA lesions surrounding normal white matter and normal control group white matter, including three parameters: f value (perfusion fraction), D value (true diffusion coefficient), D* (pseudo-diffusion coefficient). Results f value and D value is increased with statistical significance, when LA white matter lesions compared to LA surrounding normal white matter. There is no statistical significance in D* between the two groups. When LA white matter lesions compared to normal control group white matter, f value is increased, but without statistical significance. D value is increased and D* decreased with statistical significance. There is no statistical significance about f, D and D* value, when LA surrounding normal white matter compared to normal control group white matter. Conclusion Intravoxel incoherent motion diffusion weighted imaging can quantitatively evaluate the brain white matter microstructure changes and microcirculation perfusion.