Abstract: As a clinical, etiological and pathological diagnosis, C3 glomerulopathy（C3G） refers to a diverse group of rare kidney diseases characterized by complement dysregulation in fluid phase and glomerular microenvironment. As a non-specific condition, membranoproliferative glomerulonephritis（MPGN） is one of the pathological changes of renal biopsy under light microscope. The light microscopic pathological change of C3G is predominantly membranous MPGN while C3G is a major cause of MPGN. This review summarized the etiologies, clinical manifestations and pathological features of C3G and MPGN. C3G may be used as an initial or a major clinical diagnosis while MPGN is merely a light microscopic pathological change. When renal biopsy hints at MPGN, primary etiology should be actively sought for a definite diagnosis.