RAPD analysis of DNA variation in somaclones of Hypericum perforatum which passed through one or two cycles of in vitro regeneration revealed great variation among the donor plants from which the somaclones were regenerated. The donor plants represented either seed-derived plants or the seed progeny of first-cycle somaclones. The variation among them may indicate natural genetic variation in Hypericum perforatum. In addition, no differences were found in the RAPD profiles of 51 first-cycle somaclones within groups originated from 7 donor plants. This may point to relative stability of the Hypericum perforatum genome under given conditions of in vitro regeneration. One polymorphic band was found in 3 of 51 RAPD profiles of second-cycle somaclones, perhaps an effect of repeated in vitro regeneration on DNA changes. Study of DNA variation among 75 Hypericum perforatum progenies derived from 8 mother plants indicates the prevalence of the apomictic mode of reproduction. Analysis of 47 seed progenies of diploid somaclones derived from 5 R3 plants may suggest the sexual mode of reproduction.