This study developed and validated a predictive model for screening the high risk of IgAN with the following advantages: (1) all patients enrolled had primary glomerular diseases confirmed by renal biopsy; (2) combining serum IgA/C3 ratio with age, serum albumin, total cholesterol, and hematuria to establish a predictive model reduced the limitations of using only the serum IgA/C3 ratio as the differential indicator; (3) with the same modeling variables, a simple, safe, and accurate predictive model for IgAN was developed that has good prospects for clinical application. This evidence concerns the gene C3 and glomerular disorder.