Buffalo is one of the livestock which adaptive in all kinds agroecosystem with high selling value, especially for religion?s rituals. It is intereting to study, which is less studies and development program of buffaloes. The aim of this study is to identify buffalo breeding business system and feasibility analysis in rice fields plateau of north Kalimantan. This study done in 2017 at rice fields plateau agroecosystem of Krayan sub district, Nunukan district of North Kalimantan province. The methods of this study is quantitative research with cross sectional survey and purpossive random sampling for respondents determination. Primary and secondary data used for this study. Primary data were buffalo breeding business system datas from respondents, which collected used structured interviewed with questionaire. Secondary data were supporting datas from government service offices. Descriptive and inferential analysis used for this study. This result study show that buffalo farmers performance depend on areas accessibility and local agroecosystem, in terms of buffalo ownership, experiences in buffalo business, and farmer age. Buffalo reproductive performances in rice fields plateau agroecosystem of Krayan sub district, is in not good performances, in terms of birth mortality, calving rate, and sex ratio mating. Based on criterias and assumption, could be concluded that buffalo breeding business system in rice fields plateau agroecosystem of Krayan sub district, feasible to be done, eventhough on large scale. To increase buffalo performances in this area could be suggested to continously develop farmer?s knowledge by non formal training and develop mating management by using elite buffaloes stud for nature mating system or artifficial insemination form other areas (outbreeding).