A floristic inventory of grass and undergrowth was carried out in the southern block of the Yoko Forest Reserve in the Eastern Province. This study aimed to identify grasses and undergrowth, and evaluate the wealth of this areal florula. Transect methods and phytosociological survey was the approach used. A total of 116 plant species have been inventoried and are belonging to 92 genera and 44 families. Note that the dominant families and features are: Commelinaceae (7.76%) and Rubiaceae (6.90%). The relative densities of species and the highest are those of family Marantochloa congensis (174.0 feet/ha) and Marantaceae (360.0 feet/ha). The relative frequencies of the most observed species are those of Palisota barteri (3.21%) and Cola congolana (3.39%), while those of family are Arecaceae, Commelinaceae, Connaraceae, Euphorbiaceae, Lomariopsidaceae, Malvaceae, Marantaceae and Menispermaceae (6.25%). Simpson's diversity index (0.957), Shannon’s diversity index (3.619) and equitability (0.798) revealed that this florula is diversified and its species are well distributed. It is thus desirable that this study is extended to other forest reserves and forest groupings of Kisangani city and its surroundings in order to establish a better database necessary for the sustainable management of the classified forests and other sites of
high value for the conservation.