Canopy seed banks and delayed release adaptations are particularly prominent in sandy ecosystems. In this study, we investigated the size, seed vigor, supplementary effect on soil seed bank, and the retention dynamics of Sophora alopecuroide canopy seed bank in a desert grassland of Huocheng County, Xinjiang. The result showed that canopy had 271±124 beans·m^-2, and the number of complete seeds reached 144±138 beans·m^-2 which contributed to the canopy seed bank. After mechanical damage, the germination rate reached 76.98%±11.89%, seed vigor index was 72.44±39.01, which indicated that canopy seed bank could keep higher seed vigor. Canopy seed bank lasted about nine months. As a result, canopy seed bank could be an effective supplement to the soil seed bank, and both of them performed as effective supply bank of propagules during population regeneration and community succession. The results would be helpful to understand the reproductive characteristics, reveal the bioecological mechanism of its malignant invasion, and provide theoretical support for management of grassland ecosystem in the Ili River Valley.