The Oxford classification using histopathological finding was developed and reported to predict outcome of IgA nephropathy (IgAN). The upper reference limit (95th percentile) for the number of globally sclerotic glomeruli (GSG) expected on biopsy according to age was determined. And based on the ag-adjusted reference of upper limits for GSG, the prognosis of chronic kidney disease is best predicted independently. We aimed to determine whether the prognosis of IgAN is affected by the age-adjusted number of GSG independently of T score of the Oxford classification. Patients with a biopsy-proven IgAN were enrolled in a single center. Patients with a follow-up of less than one year were excluded. A total of 217 patients were studied retrospectively. The renal biopsy pathologic examination was reviewed by two pathological experts using Oxford classification; METS-C score. When there are more GSG than the upper reference limit (95th percentile) for the number of GSG expected on biopsy according to age, it is defined as GSG abnormal for age. The primary outcomes were annual eGFR decline and eGFR level 40% lower than baseline eGFR lasting at least one month. Patients with GSG abnormal for age was 111. They were associated with higher serum creatinine, more 24hr urine protein, higher blood pressure, lower eGFR, and higher MEST-C scores (Table1). In multivariable Cox model, patients of GSG abnormal for age had more rapid eGFR decline (ΔeGFR -2.382, P = 0.019, Table 2A) and poor renal outcome (HR 27.675 [2.307 – 331.997], Table 2B). Kaplan-Meyer curve showed that patients in GSG abnormal for age developed more renal outcome, especially in patients with T score of 0 (Figure, p-value< 0.001, by log-rank test).   Our results suggest that the number of age-adjusted GSG might be an independent prognostic factor of IgAN in addition to Oxford classification