This study aimed to assess the vegetation structures and diversity in grazing land of the Abijata Shala Lake National Park in Ethiopia. The stratification of the site was done before sampling based on grazing intensity. Random sampling techniques were used for species composition, diversity and vegetation structure. Two grazing intensities, 12 sampling sites, and five plots per sample site were used that = 120 samples all totaled. The height and diameter-at-breast-height (DBH) of woody vegetation was estimated by clinometers and caliper. A total of 64 species that belonged into 27 families were identified and recorded, whereas 24 were woody and 40 were herbaceous species. The height of woody vegetation ranges from 2m to 25m and classified into five classes as (2-5m, 5.1-10m, 10.1-15m, and 15.1-20m and 20.1-25m). In addition, the DBH was also classified into six categories as (<10 cm, 10-20cm, 20-30cm, 30-40cm, 40-50cm and >50cm). The high proportions (45.35%) of woody species were found in (10-20cm) DBH classes in the heavily grazed area compared to a lower proportion (38.78%) in the low grazed area. The densities of woody trees decreased as the height and the DBH increased. Furthermore, the herbaceous species had a significant variation (P<0.05) of species richness, diversity and evenness with grazing pressures. Generally, the overgrazing has negative impacts on the vegetation structure, diversity and vegetation biomasses. Therefore, the sustainable management and intervention of community based conservation was suggested to sustain the ecosystem health and abundances of vegetations.