Abstract: In this paper, study on the ecological characters of the medicinal herb Knoxia valerianoides Thorel et pitard shows that in China ,the distribution of Knoxia valerianoides Thorel et Pitard extend through the tropical zone. South Asia subtropical zone and Central Asia subtropical zone. It is mainly distributed in laterite and red soils which orignated from granite. The limit of vertical distribution gradually ascends as the distribution area extend from east to west. The vegetation of the distribution area is tropical and subtropical evergreen broard-leaved forest. portion of which have evolved into grass-slopes. This medicinal herb is mesophyllous heliophyte, with a peak in its growth phase coinciding with that of the annual rainfall.