Abstract: As a second-class endangered plant in China, Coptis omeiensis (Chen) C. Y. Cheng has high medical value but is not cultivated. To determine the endangering factors, we described and analyzed in detail the life cycle and reproductive and ecological characteristics of C. omeiensis. We dissected and recorded the growth of various parts of the flower and mixed bud by field observation and general anatomical lens and digital microscopy (Motic BA200) and observed pollen grains by scanning electron microscopy (Hitachi S-450). The life cycle of C. omeiensis can be divided into 4 periods and the life expectancy is up to 15 years from seed germination to natural death. C. omeiensis exhibits sexual propagation and has no paraclade in asexual propagation. The terminal bud was mixed and was composed of the lateral inflorescence and a normal bud. Various parts of the proterogynous flower developed normally. The petal and stamen primordia were homologous. Pollen grains were 16 to 24 μm in diameter and had spinulose ornamentation. The seed contained narrow aliform processes on the ventral side, and germinated in the second year for its embryo after-ripening. In addition, the most suitable growth environments happened in damp rocks at 1 100 to 1 700 m elevation. Eco-environmental factors such as rainfall, temperature, humidity and light are important to the survival and distribution of this endangered plant.