This thesis elaborated the concept of civil society in the world and in the Republic of Croatia, and the concept has changed through European history. Historical development of Croatian civil society is designed in five parts: the period before 1990, the new Croatian constitution, modifications in year 2000, formal legal framework of civil society in the Republic of Croatia and the current typology of civil society organizations in the Republic of Croatia which encompasses: associations, foundations, unions, employers' organizations, and relegious communitys. Then, the concept of the Civil Society Index will be elaborated, which is a participative needs assessment and tool for planning the activities of civil society. Comparative analysis of religious communities in the City of Zagreb and Osječko-baranjska County was conducted in the final work, then the social context of the activities of religious communities, their legal framework, the financing of religious communities as well as the International Treaties between the Republic of Croatia and the Holy See were elaborated.