This book explores the interaction of Eugene O' Neill's characters with their living space which includes their interaction with the audience, the world outside that they envision through the opening of a window or a door; and their interaction with every object that is present on stage. This interaction does have a psychological and metaphysical impact on the characters. Even the costumes they wear and the books that they possess have a specific purpose. These unleash the mood and the psychological outlook of the characters. A mere change in costume often tells us about the change in psychological outlook. The objective of this book is to explore this psychological and metaphysical outlook of the characters in selected plays of O' Neill. The first chapter gives a detailed introduction of the research work. In second chapter, O'Neill's use of dramatic space is explored. The third chapter focuses on metaphysical interaction of characters with their space and the fourth chapter entails psychological impact.