Globalization has expedited the developments in communication and information technology and use of these technologies and easy access to them has transformed international conditions. These structural and substantive changes in international system have changed general diplomacy to an instrument by means of which governments can achieve their national goals in their relations with other countries and also at international stage. Directing public opinion, role of visual, audio and written media having international audience, impact of immigration, internationalization of thoughts and ideas, expanding role of NGOs, exchange of cultures, movements and easy communication among elites, involvement of civil society in political-international affairs, and globalization of cultures are among fields that general diplomacy can rely on and unify them to influence people’ s minds and government policies. This paper aims at studying general diplomacy as an effective instrument in foreign policy through four sections. First, it studies the effects and consequences of recent global changes in diplomacy. Second, the concept of general diplomacy and its difference with official (traditional) diplomacy, publicity, and domestic policy are studied. Third, dimensions and practical fields of this phenomenon in foreign relations of countries, and at the end the effects and roles of general diplomacy in foreign policy are explained and analyzed.