Abstract: Objective : To investigate MR manifestation of lumbar myeloid inverse conversion and differential diagnosis of common pathogeny. Methods : To collect the clinical,laboratory and image data of 14 patients which MR manifest lumbar myeloid inverse conversion in our hospital,among them 6cases of metastatic tumor,2cases of multipl myeloma,1 cases of myelofibrosis,5cases of tumor after chemotherapy. Results : 5 cases' lumbar MR manifest uniformity hypo-signal in T₁WI,uniformity hypo-signal in T₂WI.9 cases' lumbar MR manifest multiple patchy and mottling hypo-signal under equi-signal background in T₁WI,and isparate numerus hypo-signal under equi-signal background in T₂WI,among them 3cases involved in lumbar accompaniment,2cases emerged tumeur in the side of the lumbar and in epidural space respective. Conclusion : Lumbar myeloid inverse conversion generated in the patients of metastatic tumor,multiple myeloma,myelofibrosis and tumor after chemo-therapy,which MR manifestation is less of specific characteristic,definitely diagnoses required to combined with the data of clinic,laboratory and examination.