Objective To study the clinicopathological features of patients with IgA nephropathy（IgAN） with foot process fusion，and to explore the effect of foot process fusion on renal function in patients with IgAN. Methods The data on 219 patients with IgA nephropathy in our hospital were retrospectively analyzed. According to the appearance of foot processes on electron microscopy，the patients were divided into a group with extensive fusion（≥50% fusion）of foot process（40 patients，18.3%）and a group with no obvious lesion（lesion⁃freeor <50% fusion）of foot process（179 patients，81.7%）. Results Levels of serum creatinine，urea nitrogen，uric acid，dia⁃ stolic blood pressure，cholesterol，triglyceride，low density lipoprotein（LDL）and urinary protein were higher in the group with extensive foot process fusion than in the group without obvious lesions，while serum albumin level and estimated glomerular filtration rate（EGFR）were lower. Increased diastolic blood pressure，urea nitrogen and LDL were independent risk factors for extensive foot process fusion. Logistic results showed that extensive foot pro⁃ cess fusion was an independent risk factor for renal dysfunction in IgA nephropathy（P<0.05）. Conclusions The clinical manifestations are more severe in IgAN patients with extensive foot process fusion. Extensive foot process fusion is an important factor affecting renal function in patients with IgAN.