Abstract: ob＜x＞jective To report a family of CSF1R associated leukoencephalopathy caused by a mutation of the colony stimulating factor 1 receptor CSF1R) gene and to analyze the neuroimaging features of the proband and the family patients. Methods A pedigree of the leukoencephalopathy was collected. The proband and some family members in the family were investigated for history, physical examination, neuropsychological assessment, MRI and gene detection. Results There were 4 patients in the 3 generation of the family. The first symptoms were gait instability, emotional disorder and memory loss respectively. MRI findings of the 3 patients showed bilateral paraventricular and semioval center symmetrical white matter lesions, with varying degrees of ventricular enlargement, brain atrophy, corpus callosum thinning, septum pellucidum formation, of which 1 case showed persistent high signal on DWI. Gene detection showed that there was a splicing mutation in CSF1R gene, c.2319 + 1C > A. Conclusion Extensive symmetrical white matter lesions，high signal intensity for long time on Diffusion weighted imaging, septum pellucidum formation and paraventricular calcification are helpful for the early diagnosis of CSF1R related leukoencephalopathy