The study was conducted in two settlements of ethnic communities in Triyuga municipality of Udayapur district, Nepal. The main objective of the study was to prepare an inventory of cultivated diversity of plants and animal species by the ethnic communities in the research site and their use in farming and in sustaining the livelihoods. The study has been based on data collected through personal interview with the farmers, focus group discussion, non-participant observation as primary source and also on secondary data collected from related publications of various organizations. The study has revealed that farmers grew and maintained different varieties and landraces of cereals, vegetables, fruits, fodder crops and livestock species and were found utilizing different species of plants and animals in farming and in sustaining their livelihoods. This justifies that the traditional ways of managing the natural resources have often resulted in landscapes of relatively high biodiversity value, compared with those associated with modern practices. [Pawan Singh Bhandari. Ethnic Communities Own Agrobiodiversity Richness. International Journal of Agricultural Science, Research and Technology, 2012; 2(1):9-16].