Abstract: According to the observations under the climate at 1700 meters above sea level of mountainous district, the annual periodity of growth and development of fritillary (Fritillaria pallidifora Schrenk.) is briefly described as folldowing: The young shoot sprouts out of the bulb and emerges from the soil in April every year, and forms flowers and fruits in succession. During this period the nutrients of underground bulbs exhaust themselves and a new buld is thereby regenerated. In the middle of June, the aerial part dried up. The regeneration bud in the underground bulb differentiats itself under the condition of 8–22 ℃ in surmruer and an axillary bud is simultaneously initiated. The bulb thus formed dormants in the winter. The growing period of fritillary is only 80–90 days above the ground and 270–280 days beneath the ground. Hence, the whole developmental process of a regeneration bud of fritillary has to pass through three successive growing seasons under the normal conditions in which the growth confined to the inside of bulb lengthens to 600 days approximately. With comparison of the other bulbous plants the characteristics of the development of fritillary may be defined as follows: 1. The regeneration bulb can be formed under the condition of short-day light on even under complete darkness. In contrast with fritillary, the formation of new bulb of onion and other bulbous plants occurs under the longdag light. 2. It is certainly known that a critical size of rhizome or bulb is required for flower formation of Iris and tulip. A similar phenomena has been observed for fritillary in the present experiment. The critical size of bulb for flower initiation of fritillary is taken by us as 1.8–2.7 girfresh weight and 1.2–2.2 cm in diameter. This has nothing to do with the age of the bulb. 3. Different optimum tempertures are neccessary for various developmental stages of fritillary respeetivtly. The normal development periodicity of fritillary may be modified by the onset of dormancy under the condition of low temperatures. Using this method, a secondary shoot will grow up in one growing season. This is in confirmation of the report on the experiment of an other fritillary.