Bay of Algiers is situated at the heart of the Algerian capital, where the population density and urban important, and many factories and commercial activities, making it vulnerable to pollution, especially along the coast, in addition to climate change that result on the planet, all this lead us to study the impact on the coast of the Bay of Algiers, and its exposure to risks of erosion and marine intrusion. The aim of this work is the perception of vulnerable coastal areas, by determining the Coastal Vulnerability Index (CVI) at the level of the bay of Algiers, through reliance on physical factors. Through the Geographic Information System (GIS), we can process and analyze the information, and propose technical solutions to protect and manage the coastal, especially the sensitive areas near river mouths, a place of exchange and interaction of intense sediment transport.