This study determined the impact of Tebuthiuron application on plant biodiversity over three years at Neudamm farm. A total of 36 quadrats (1 m x 1 m) were collected from three belt transects (50 m x 5 m) per each treatment to record the grasses plant density, species composition, dry matter and ground cover. Woody plant density, heights and canopy diameters were measured in each belt transects (50 m x 5 m). A General Linear Model (GLM) procedure of SAS (2007) was used for analyses. The herbaceous biomass production was significantly higher (P < 0.05) in the chemically treated site of 2015 (975 Kg DM ha-1) and least in the other two sites. The chemically-treated site of 2016 had more significant (P < 0.05) ground cover percentage than the other treatment sites. The canopy cover and woody plant densities in all woody height categories were higher (P < 0.05) in control and chemically treated site of 2017 than the other two sites. The study concluded that the Tebuthiuron had impacted on the plant biodiversity of treated rangelands by improving the grass plant species, biomass yields and reduced bush density. The study recommends that aftercare practices and application of arboricides be carried out routinely to allow herbaceous plants recovery. Keywords: Bush encroachment, arboricides, plant density, biomass production, canopy.