This research is motivated by the tendency that undergrowth vegetation is still neglected and is still not being considered as a component of the forest ecosystem. In fact, when viewed from the function and role undergrowth vegetation, it is also very large in maintaining forest ecosystems such as in terms of maintaining soil structure, soil fertility, maintaining soil temperature in the process of water infiltration, holding back surface erosion (run off), a source of food for animals. The purpose of this study was to determine the types of undergrowth vegetation and to determine the relationship between species (associations) between undergrowth species in the Industrial Plantation Forest area of Samarinda State Agricultural Polytechnic. The method used in this research is a plot made with a single plot method where the plot is made purposively on the land to be studied with an area of 58 x 26 m2 in which there are 40 sub-plots measuring 2 x 2 meters with 40 sub plots with evenly distributed placement in the plot. (systematic). From the results of research on the types of undergrowth vegetation in the HTI area of Samarinda State Agricultural Polytechnic: the presence of undergrowth vegetation species around HTI Politani Samarinda has a diversity of 26 species, 24 orders, 22 families and an abundance of 688 individuals.

Keywords : Composition, Association, Undergrowth Vegetation and Industrial Plant Forest