IgAN is the most common primary glomerular disease in China. It can occur at any age and progress chronically. Current data show that about 20%~40% of patients develop to end-stage kidney in 10~20 years. There are many factors contributing to the progress of IgAN. In addition to the recognized immune factors, many metabolic factors such as body mass index, insulin resistance and hyperuricemia have been reported in recent years, which are also related to the progress of IgAN. IgAN is not uncommon in patients with high BMI and kidney diseases, which are not all obesity-related nephropathy. This paper reviews the correlation between high BMI index and IgAN.