Samastipur is a district head quarters and is one of the Rly divisional head quarters of East Central Rly of North Bihar. Its ancient name is Samsuddinpur. It is on the main Rly line of Howrah and Gorakhpur.there are about bout 13 lakhs people live here. Large part of the people are agriculturists. Samastipur is best known for Agricultural University, RAU, Pusa, which is near about 20 kilometers away from the district headquarter. There are so many establishments at samastipur such as Railways workshop, Rilway Hospital, DRM Office, some constituent colleges, High schools, diesel shed, Collectorate, Sub Divisional Office, State Bank, Central Bank Registration office, Court complex, DSE office, a few public schools and Kendriya Vidyalaya. There are also two mills, one of them Muktapur Jute mill and another Hassanpur Sugar Mill, but now-a- days they are not running.