An efficient method for production of plantlets from horseradish hairy roots (Armoracia rusticana) was developed and the plantlets were encapsulated and used as artificial seeds. Hairy root fragments were obtained by fragmentation of hairy roots in a blender after the foot growth, A fragmentation time of 30 s gave the best result on the plantlet formation. Treatment of the hairy roots with naphthaleneacetic acid (NAA, 1.0 mg/l) prior to fragmentation resulted in a decrease In the time required for hairy root growth. Kinetin supplementation of 0.1 mg/l after fragmentation (in the plantlet formation stage) resulted in the highest number of plantlets. Furthermore, we found that the kinetin treatment led to a change in the size distribution of plantlets and inhibition of root elongation, which facilitated encapsulation of plantlets. Although the frequency of plantlet development was significantly reduced by encapsulation in 2% calcium alginate beads, dehydration treatment before the encapsulation strongly improved the plantlet development frequency.