The water culture experiment of Houttuynia cordata of the medicinal plant was carried out, and basic study on 137Cs accumulation characteristic and internal circulation in H.cordata in the fruiting stage was investigated since the flowering season.
H. cordata accumulated 80 % of 137Cs absorbed unlike K to the root, rhizome, terminal bud of the underground part for the rhizome reproduction. 137Cs content to the young leaf, spike, involucre increased in the flowering season. Thereafter, 137Cs was recirculated to the developing organs in second generations such as the rhizome and bud.