Abstract: The biology population of Nomocharis mairei Levl. which comes from Canshan Moun-tains, Dali, Yunnan, was investigated in this paper. The morphological characters were statistically analyzed in the population. The characters are as follows the plant height, internodal length, leaf number of cycle, length and broad of leaf, flower number of individual, length and broad of inner or outer petal, diameter and number of dot on inner of outer etal. The polymorphism of the characters and their frequencies were describedin the population. As a result, all characters investigated appear obvious polymorphism, which is different one another in the va-riation patterns. Among the characters, the plant height, length and broad of leaf, flower number of individual, length and broad of inner of outer petal are quantitative characters which are heritable and environmental effecting.

Key words: Nomocharis mairei