Abstract: The air quality model EPICC-Model was adopted to investigate the seasonal differences in the simulation of SNA components under different emission inventories over the Beijing-Tianjin-Hebei region. February (winter) and July 2023 (summer) were selected as representative periods, and simulations were conducted with six emission inventories (MEIC, ABaCAS, CAQIEI, EDGAR, HTAPv3, and CEDS). The results indicate that simulations based on all emission inventories exhibit a consistent seasonal pattern. The total SNA concentration in winter is approximately 55.5% - 65.6% higher than in summer. Nitrate dominates the SNA composition in winter, whereas its fraction decreases in summer while the fraction of sulfate increases. Based on the concentration differences simulated using different emission inventories, the uncertainties of sulfate, nitrate, and ammonium are all higher in summer than in winter. Among the three components, nitrate exhibits the largest seasonal variation in uncertainty, with its coefficient of variation (CV) approximately 67% higher in summer than in winter. Compared with ground-based observations, all bottom-up inventories except EDGAR generally underestimate sulfate and ammonium concentrations in both winter and summer. Nitrate is underestimated in all bottom-up inventories during summer, and in winter it remains underestimated except in HTAPv3. In contrast, the top-down CAQIEI inventory reproduces SNA component concentrations reasonably well in both seasons. These results highlight the differences in SNA simulations and their uncertainties across emission inventories, providing a scientific basis for understanding and reducing uncertainties in SNA modeling.