This study was aimed to investigate the diversity and abundance of woody plant species of Assosa forest gene bank. An inventory was made to collect the required data and sample plot of size 20mx20m quadrant was used for this particular study. Sixteen quadrates of sample plot were systematically laid down with an interval of 100 m along four transect lines. Shannon-Wiener index was applied to quantify species diversity, richness, and evenness. A total of 44 woody plant species representing 34 genera and 26 families of were identified. From 44 identified woody plant species 948 number of individual plants were counted and recorded. Most of woody plant species counted and recorded from the Assosa forest field gene bank were belongs to Combretaceae family. The current study reveal that Assosa forest field gene bank has more diverse (H=3.17), unevenly distributed (E=0.46) and abundance of all individuals of plant species.