The research project "Blue bull 'Nilgai' (Boselaphus tragocamelus): Demography, Carrying Capacity, Conflict and Participatory Conservation Action Plan in Lumbini Development Trust" was carried out to estimate population, carrying capacity of Lumbini Development Trust (LDT) area for Blue bull and assess the crop damage pattern of Blue bull. Finally project has prepared the Participatory Conservation Action Plan (PCAP) for Blue bull in LDT area. Forty one Nilgai were counted in the potential LDT area (5.14 sq.km). The population density of Blue bull was 8 individual/sq.km with the sex ratio of 2:3 (male:female). Approximately 79 percent of the area was plantation forest and remaining 21 percent area was grass and open land. Carrying capacity of the LDT area was 125 numbers of Nilgai for the winter season. High quantity of rice crop was damaged by Nilgai followed by wheat, mustard, maize and lentil, black gram, pigeon pea.