Coastal mudflats reclamation activities show a strong influence on soil properties and microbial community activity, which drive soil carbon and nitrogen cycling. Studies have found there is a shift of bacterial community with reclamation time. However, effects of reclamation time on the soil archaeal community are still largely unknown.Here, we determined soil properties and archaeal community in the soil profiles (0-15, 15-30, 30-45 cm) of different reclaimed sites with different reclamation ages (R12: 12-year; R38: 38-year; R68: 68-year; R100: 100-year) in Rudong County, Jiangsu, China. Soil archaeal communities were identified via Illumina high-throughput sequencing. Soil archaeal communities were dominated by two phyla, the Crenarchaeota (82.1-93.3%) and Thermoplasmatota (4.2-17.9%), which are associated with nitrogen cycle (Nitrosopumilaceae, Nitrososphaeraceae, and Nitrosotaleaceae) and organic carbon metabolism (Marine_Group_II), respectively. Ammonia oxidizing archaea showed a divergent response to the reclamation, i.e. Nitrosotaleaceae increased with reclamation time whereas Nitrosopumilaceae showed a decreasing trend. Soil total carbon, total nitrogen, pH, EC, C:N ratio, NO 3 À -N content, soil moisture, depth, and reclamation age determined archaeal community distribution in our reclaimed sites. Our findings suggest that both reclamation time and soil depth significantly shaped the archaeal community composition, and then in turn modulated soil carbon and nitrogen cycling in the reclaimed mudflats.