Our work aims to study the ecology of a rare and endemic species, belonging to the family Liliaceae Fritillaria oranensis Pomel, on the mountain of Tessala, mountainous area of western Algeria. Because of the rarity of the chosen taxon, we wanted to explain the causes of its rarity. The work is based on the observation of the species and represents a contribution to the analysis of the stationary conditions of its habitat by an approach of evaluation of the ecological and biological parameters. Then a follow-up of the population of Fritillaria oranensis Pomel is started. This population is composed of only six individuals present only on one station. This observation confirms the status of the rarity of this endemic species. The future of this species is in danger of extinction in the studied zone.