Present book is an outcome of Ph.D work, main objective of the present study is to analyze the performance of Single Line Administration (SLA) in the development of the tribal areas of Himachal Pradesh. As, Single Line Administration was introduced in the Himachal Pradesh for the better and speedy development of the tribal areas of the state. In total geographical area of Himachal Pradesh tribal area contribute 42 per cent and 4.02 per cent population to the total population. Due to tough geo-physical conditions it was a great challenge before the government to deliver the basic services to the people living in tribal areas of the state as the whole tribal areas remains covered under heavy snow for the four to six month in a year. After a long churning at the policies maker level they find out the solution of Single Line Administration and initially it was introduced in ITDP Pangi in 1986. After the successful result caused by the SLA, it was further expanded to the rest of ITDPs of the state. So, in the present book there are some detail regarding the performance made by SLA in the development of the tribal area especially in ITDP Pangi where it was first implemented .