Mesona is an endemic and economical crop in Taiwan. It is distributed widely in hillsides and fields of low to medium altitude in Taiwan. The information about Mesona(Mesona procumbens) in genetics was limited since seldom researches had been done on Mesona, which makes breeding program difficult. The purpose of the present study is to investigate the population variation of Mesona based on morphological characters in habitats, phenotypic characters in a field, DNA polymorphisms and gel-forming characters. The information of population diversity obtained from the present study may serve as a reference for breeding, gene pool diversity, and germplasm conservation program of Mesona.