Sivasagar district {Pron: ˈsɪvəˌsʌgə(r) or ˈʃɪvəˌsʌgə(r)} (Assamese: শিৱসাগৰ জিলা), formerly known as Sibsagar, is one of the 32 districts of Assam state in north-eastern India. Sivasagar city is the administrative headquarters of this district.It is known for its rich and diverse biodiversity. The districts covers an area of 2668 square kilometers as against total area of 78438 square kilometers of Assam as per census of 2001. The district comprises two sub-divisions – Sivasagar and Nazira.