A survey was conducted to identify leguminous nitrogen fixing herb, shrub, climber and tree species from terai to tree-line (60- 3000 m) in the eastern part of Nepal. Among species found, 29.8% were trees, 26.9% shrubs, 26.3% herbs and 17.0% climber species in three sub-families of Fabaceae. A maximum 63.7% species were recorded at lower altitude i.e., 60-1000 m, followed by 27.9% in 1000-2000 m, 6.4% in 2000-3000 m and 1.7% above 3000 m. However, no tree species were recorded beyond 2000 m and no shrub and climbers above 3000 m except Astragalus donianus , A. sikkimensis and Parochetus communis . Percentages of nodulated species within sub-families were 99, 86 and 8 for Papilionoideae, Mimosoideae and Caesalpinioideae, respectively. Overall, 94.3, 80.0, 79.3, 77.8% nodulated and 5.7, 20.0, 20.7, 22.2% non-nodulated species were recorded in herb, shrub, climber and trees respectively in all the three sub-families.