The study was conducted in the smallholder farmerâ€™s landscape of Elfeta District, West ShoarnZone, and Oromia Regional State, Ethiopia. The objective of this study was to assess the treernspecies composition, structure, diversity, management practices and their socioeconomicrnimportances. Three kebeles representing three different elevations highland, midland andrnlowland agro-ecology were selected. A total of 21 households were randomly selected to collectrnsocioeconomic data and other information. Data on tree species diversity in crop fields wasrncollected by categorizing households as rich, medium and poor. Tree species inventory wasrncarried out on 21 plots (each, 50mx100m) in the smallholderâ€™s farmerâ€™s landscape. For treernspecies â‰¥ 5cm DBH, measurements of DBH and tree height were taken. A total of 78 tree speciesrnbelonging to 48 families were recorded in the farmlands of the study area. 322 individuals treernspecies were identified in the three study areas, of which 165 were found at lowland (Etisakoyernkebele), 103 species in midland (Ambelta Godeti kebele) and 54 species in highlandrn(Harotufticha kebele) farmers landscape. The study indicated that the tree species diversityrnindices and species richness were higher at lowland than midland and highland agro-ecologicalrnzones. On the other hand, farmers at the study site also have developed experiences of treernspecies preferences for different purposes. According to the respondents, the main purposes ofrnpreference or retaining tree species on their farmland were for soil fertility, firewood, timberrnproduction, fencing, animal fodder, fruit, income generation, house construction, charcoalrnproduction and other purposes. Even if the diversity of tree species is better in the study, theyrnneed a series of management to save and sustain for the future generations to overcome thernsocio-economic and environmental problems.