Abstract: In this paper, the developmental rhythm of the underground organs of Fritillaria ussuriensis was studied according to the individual development. The bulb of F. ussuriensis plays a leading role in its life. Both primary root and fibrous root systems are short-lived. The developmental characteristic of the fibrous root system is biennial total renewal type. There are no starch grains discovered in primary and fibrous root cells at any season. That may be corelated with that the bulb is a storage organ.

Key words: Fritillaria ussuriensis, Bulb, Root system, Developmental rhythm