Hailar District (Mongolian: ᠬᠠᠶᠢᠯᠠᠷ ᠲᠣᠭᠣᠷᠢᠭ "Qayilar toɣoriɣ" Хайлаар тойрог, Cyrillic: Хайлаар дүүрэг, "Khailaar düüreg"; ) is an urban district that serves as the seat of the prefecture-level city Hulunbuir in northeastern Inner Mongolia, China. Hulunbuir, due to its massive size, is a city in administrative terms only, being mainly grassland and rural. Hailar, therefore, is a "de facto" city