[Objectives] To study the underground stem tissue structure and agronomic traits of different populations of wild Houttuynia cordata Thumb. [Methods] 8 different populations of wild Houttuynia cordata Thumb. in southern China were selected,the preliminary study was carried out about underground stem tissue structure( stem wall thickness,underground stem cross section diameter,medullary cavity,large vascular bundle area,small vascular bundle area,and number of vascular bundles),and main agronomic traits of aboveground and underground parts. [Results]There were significant differences in the und...