The flora of the INERA Kiyaka Forest Reserve (National Institute of Agricultural Research and Studies of Kiyaka), covering 1,160 ha, located 75 km southeast of Kikwit town, was studied with the aim of analyzing the composition, to determine the richness, the floristic diversity and to study the ecological and phytogeographical spectra of inventoried taxa. To do this, 52 plots of 1,250 m2 each. Thus, 6.5 ha have been delimited to make floristic inventories and to collect botanical samples. The results obtained reveal, at the present stage, the existence of 182 infrageneric vascular units, including 178 Magnoliophyta with a high level of Magnoliopsida, ie 90% and 10% of Liliopsida. This flora is dominated by Rubiaceae, Olacaceae, Euphorbiaceae, Fabaceae, Dichapetalaceae, Marantaceae, Malvaceae / Sterculioideae, Moraceae, Icacinaceae, Apocynaceae, Ochnaceae, Annonaceae, Clusiaceae, Connaraceae and Sapotaceae, while the ecological and phytogeographic spectra of this species are analyzed. florulum shows a clear prevalence of phanerophyte species from the sarcochores, mesophylls and guinea-Congolese. The impact of the very obvious anthropogenic activities in this forest reserve, evidenced by the existence of the fallow lands caused and dominated by Chromolaena odorata induce a grassy physiognomy in extension.