Abstract: To investigate the effects of different preservation treatments on the quality of winter jujube (Ziziphus jujuba Mill. cv. Dongzao) during storage at room temperature, Huanghua winter jujubes were used as test material. The jujubes were treated with 1-methylcyclopropene (1-MCP), chitosan (CTS), nano-selenium (nano-Se), 1-MCP + CTS, and 1-MCP + CTS + nano-Se treatments, with water soaking serving as the control group. The jujubes were stored for 21 days at room temperature (22 ℃ ± 1 ℃) and a relative humidity of 60%–70%, and relevant quality parameters were measured to identify the most suitable preservation method. The results indicated that, compared with other treatments, the 1-MCP + CTS + nano-Se treatment demonstrated a significant advantage in delaying the senescence of winter jujubes during storage. This treatment not only delayed the onset of respiratory and ethylene peaks, increased peroxidase (POD) activity and glutathione (GSH) content, and reduced the accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), but also increased the content of pectin, cellulose, and hemicellulose in the cell walls of winter jujubes, slowed the decline in firmness and soluble solids content, and significantly reduced the fruit rot rate, weight loss rate, and reddening index. Furthermore, the 1-MCP + CTS + nano-Se treatment enhanced phenylalanine ammonia-lyase (PAL) activity and effectively increased the flavonoid and selenium contents in the fruit, achieving selenium biofortification and improved functional quality while delaying fruit senescence.In summary, the 1-MCP + CTS + nano-Se treatment is proven to be an effective and innovative preservation technique for winter jujubes, offering novel theoretical and technical references for the research and exploitation of postharvest storage approaches for winter jujubes.