Objective: To explore the clinical significance of C1q and IgM glomerular deposition in adult idiopathic membranous nephropathy (IMN). Methods: Patients with biopsy-proven IMN from April 2016 to September 2018 in Department of Nephropathy of Affiliated Yantai Yuhuangding Hospital of Qingdao University were enrolled retrospectively. And renal specimens were evaluated with electron microscopy in the First Hospital of Peking University. C1q and IgM on the glomeruli were detected by direct immunofluorescence. Clinical data were compared between patients with and without C1q/IgM deposition. Results: There were no significant differences in age, sex, 24-urine protein, creatinine, uric acid, total cholesterol, triglyceride, lipoprotein(a), serum IgG, IgA, C3, C4 between patients with and without C1q deposition as well as with and without IgM deposition. Patients with C1q deposition had lower level of serum albumin (P=0.04), had higher level remission rate and had higher level of IgM deposition (P=0.027, P=0.011, respectively). Patients with IgM deposition presented with higher serum IgM (P=0.015). Conclusion: Patients with IMN and C1q deposition showed the lower level of serum albumin. However, they had the higher remission rate, which indicate that the C1q-positive might seem to respond more quickly to the immunosuppressive therapy compared with the C1q-negative. And it may serve as the guidance of clinical prognosis.