Seed storage longevity of Hosta sieboldiana (Lodd.) Engler was studied. Mature and immature seeds of H. sieboldiana were stored immediately after collection at −20 °C and 5 °C with a moisture content of about 65%. In addition, the seeds were dried to either about 10% or 5% moisture content (MC) and then stored at either −20 °C or 5 °C. Seeds of H. sieboldiana were desiccation-tolerant but short-lived, with the P50 (the time required to reduce germination to half of the maximum germination) under storage conditions ranging from 0.5 to 221.9 months and 2.3 to 56.7 months for mature and immature seeds, espectively. Seed longevity of H. sieboldiana was increased by decreasing moisture content, but the responses of the seeds to temperatures were different from typical orthodox seeds. The dry seeds of H. sieboldiana (~5% to 10% MC) lost viability more quickly at−20 °C than at 5 °C. Storage allowed immature seeds to continue some maturation, but the longevity of these seeds was generally shorter than that of the mature seeds stored under the same conditions.