Koshi Tappu wildlife reserve (KTWR) is a unique eastern flood plain Terai protected area ecosystem in Nepal. It is established as a protected area in 1976 and listed as first RAMSAR site in 1987. KTWR is famous for large remnant population wild water buffalo in Nepal and large variety of birds. Wild buffalo is the ancestor of the domestic water buffalo. Asiatic buffalo is chiefly a grazer, feeding in the morning and evenings and lying up in dense cover or submerging in wallows in midday. The study "Status, distribution, threat and habitat pattern assessment of Asiatic wild water buffalo in Koshi Tappu Wildlife Reserve" was carried out with aiming to assess population size, threat and habitat pattern. Direct census (Block count) and water holes census method was used to assess the population size by sweeping whole reserve area and water holes. For habitat pattern and threat study forest inventory was carried out and for threat assessment semi structured interview was carried with local stakeholders (herders, cattle owner, political bodies and conservation partners). The major population of wild buffalo is distributed in three isolated blocks Prakashpur, Haripur and Badgama (south duban island) and little population was in Bhagalpur blocks. The study shows population size was 237 wild buffalo in 2011 (Male 66, Female 117, first year calf 15, second year calf 39), Calf cow ratio is 0.33 and exponential growth rate is 0.097. The preferred habitat pattern used by Asiatic buffalo is sandy and open large Sacchrum grassland and riverine forest as well.