Reducing seed water content to an optimum level is an important factor in maintaining viability during long-term storage. The National Crop Genebank has established a safe and effective seed drying procedure through the last two decades' continual trial and improvement, and has completed the drying of more than 330,000 accessions of germplasm resources. In this article, the equipments and facilities of the drying procedure, optimum drying temperature, relative humidity, drying times and its use are introduced.