Micropropagated clonal plants were derived through somatic embryogenesis (from young spears in adult plants or nodal segments of seedlings) of asparagus (Asparagus officinalis L. cv 'Hiroshima Green' (2n=30), 'Mary Washington 500W'). They were cultivated by "mother stalk method" in the field of HPARC for 4 years (1990-1994) and their growth characteristics and yields were compared with those of 4 cultivars propagated by seeds or crown division. In micropropagated plants, the flower types were identical with the parent and flowering occurred simultaneously. The quality of young spears, such as head shape and colors resembled the parent. Spear size and shoot diameter of mother stalks, yield and other growth characteristics of them were more uniform than those of seed propagated cultivars. In the triploid clone of 'Hiroshima Green', the high brix content of spears and resistance to disease were maintained through propagation by somatic embryogenesis. Thus, micropropagation of superior asparagus clones through somatic embryogenesis is an economical means of producing uniform spears of high quality and yield.