International Journal of Computational Linguistics Research Heba Neama, Yasser Fouad, Mohamed Kholeef 7 1 2016 https://www.dline.info/fpaper/jdim/v13i1/v13i1_7.pdf In this paper, we proposed new model for digital library which is an extension for the 5S Model to include the semantic web layer in the structure of digital library to be 6S model for digital library. We also discuss the important role of semantic web in digital library and how are semantic web technologies affect the information retrieval accuracy. We represent the semantic layer in 6S Model by adding ontology to a digital library that satisfies the 5S model and enhance ontology by updating it automatically. This ontology is used in books classification and retrieval according to concepts in ontology.