Abstract: As a rare monoclonal gammopathy, C3 glomerulopathy with monoclonal gammopathy （C3G-MIg） is a major cause of renal injury in patients aged over 50 years. The key pathogenesis of C3G-MIg is that monoclonal immunoglobulins act as an autoantibody or directly clefts complement C3 to excessively activate the alternative pathway, leading to complement deposition and further injuring kidneys. For B cells or plasma cells producing monoclonal immunoglobulins and over-activating alternative pathway, proper treatments of C3G-MIg include a combination of supportive cares, chemotherapy and clonal antibody therapy. Focusing upon researches on C3G-MIg, this review summarized its pathogenetic mechanisms, clinical manifestations and treatment advances, providing new therapeutic rationales for C3G-MIg.