To prepare and store a large amount before a main field transplanting period comes and to reduce capital investment in a large-scale seedling raising center by storing paddy rice seedlings in a dark place in respective prescribed storage temperature range and number of days after the raising of the paddy rice seedlings is ended.

After the raising of the paddy rice seedlings is ended, they are stored in the dark place whose illuminance is less than 500Lux at the storage temperature of 7-13°C, preferably at 7.5°C, for 5-20 days, preferably less than 10 days, and the paddy rice seedlings are stored. Also, it is preferable that a storage period is less than 20 days at the storage temperature of 10°C and the storage period is less than 10 days at the storage temperature of 12.5°C.