The aim of this thesis is to describe and analyse the development of libraries on Tjörn, an island on the Swedish west coast. I have divided the thesis in two parts, one in which I will describe the libraries development between the years 1873 to 1952 in the municipality of Stenkyrka and one in which I will describe the libraries development between the years 1976 and 1985 in the municipality of Tjörn. The study is mainly based on written materials and a theoretic model will also be used in which I apply three factors, society, the libraries economy and individual actors on the library activity. The libraries in Stenkyrka during the early period were dependent of public grant from the state for their survival and the libraries were undeveloped. The society around them was poor and hardly any money or assistants came from the municipality. In the beginning of 1976 the municipality politician’s together with the county library started to reform the libraries and a chief librarian was appointed. This led to an expansion of the libraries in all of the areas. In the end of the investigated period, in 1985, the libraries had become modern public libraries.