The "no-box nursing" method was developed to save labor when raising rice seedlings and to reduce the burden of carrying heavy seedling mats. "Seed-mats" that consisted of molded rice-hull mats with hardened rice seeds, with covering soil glued onto them were developed. Polyethylene mulch was suitable as a substrate on which to place the seed-mats. The appropriate amount of covering soil ranged from 300 g to 400 g. At the beginning of raising no-box seedlings, 1.5 L of water per mat was recommended. The growth of the no-box seedlings was equal to or better than that of the conventional seedlings when the nursery period for the former was longer by four days to eight days compared to that of the conventional seedlings and covering sheets were removed when the seedlings ranged from 3 cm to 6 cm long. The no-box seedlings were equal to the conventional seedlings in growth in a paddy field, yield, and grain quality, but not in the missing percentage of transplanted seedlings. In farmers' field, the no-box seedlings decreased labor time needed to prepare for raising seedlings to about one third of that needed for the conventional seedlings. The weight of a seedling mat of the no-box seedlings was less than half of the conventional seedlings.