The present paper deals with the Ecological investigation of some selected medicinal plants at Renukoot Forest Division of Sonbhadra District in this study 16 medicinal plants such as Andrographis paniculata, Achyranthus aspera, Adhatoda Vasica, Boerhaavia diffusa, Casia tora, Euphorbia hirta, Euphorbia thymifolia, eclpta alba, phyllanthus niruri, sida cardifolia, Solanaum nigrum, Sphaeronthus indicus, Tephrosia perpurea, Vernonia cinerea have been studied during rainy season from June 2021 to September 2021 with special reference to their phytosociological aspect Viz., Density, Abundance as well as Frequency. In this investigation we found that out of Sixteen medicinal plants Cynodon dactylon have maximum value of Density (9.2) as well as abundance (9.2). Whereas Solanum nigrum have minimum value of density (1.1) and abundance (1.8), on the other hand in the respect of frequency the Cynodon dactylon, have maximum percentage of frequency (90%) and Solanum nigrum minimum percentage of frequency (10%) respectively.