Accurate assessment of the dynamic evolution process of soil organic carbon and total nitrogen content and storage holds significant implications for the formulation of efficient farmland soil management policies and comprehension of soil productivity potential. In this study, a millennium soil chronosequence was established based on the paddy soil profiles with reclamation years of 30, 60, 120, 170, 200, 280, 350, 550, 950 and 1100 years in Cixi, aiming to explore the evolution and trend of organic carbon and total nitrogen content, storage and carbon in 1 m deep tidal flat soil profiles in this area. The results revealed a decreasing trend with the increase of depth, while exhibiting an fluctuating growth trends with prolonged soil reclamation years, 30 cm and 550 year were the turning points of organic carbon and total nitrogen properties in depth and time, respectively. Approximately 61% and 54% of organic carbon and total nitrogen are stored in the 0-40cm range of the soil surface, underscoring the significance of sampling depth in organic carbon and total nitrogen retention estimation. Moreover, the organic carbon and total nitrogen storage exhibited showed a linear or exponential growth trend in the millennium formation soil chronosequence, indicating that the reclaimed soil in the study area retains a great power of sequestration for organic carbon and total nitrogen during our study period. The outcomes of this research offer theoretical underpinnings for the effective management of local soil quality, thereby contributing to the promotion of sustainable agricultural development.